Imaging apparatus, image processing apparatus, display system, and vehicle

ABSTRACT

An imaging apparatus  20  includes an image sensor  22  and a controller  33 . The image sensor  22  is configured to capture a rear area behind a vehicle  50  and generate a first video image. The controller  33  is configured to synthesize a guide wall image  80  that indicates a predicted path of the vehicle in a display region of the first video image.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of Japanese PatentApplications No. 2016-239449 filed on Dec. 9, 2016 and No. 2016-245775filed on Dec. 19, 2016, the entire contents of which are incorporatedherein by reference.

TECHNICAL FIELD

The present disclosure relates to an imaging apparatus, an imageprocessing apparatus, a display system, and a vehicle.

BACKGROUND

Conventionally, technologies for displaying video images of an outsidearea of a moving body such as a vehicle are known. For example, PTL 1set forth below discloses a technology for controlling power supply to amonitor that displays video images captured by a camera provided to avehicle.

CITATION LIST Patent Literature

PTL 1: JP-A-2009-40113

SUMMARY

An imaging apparatus according to an embodiment of the presentdisclosure includes an image sensor and a controller. The image sensorcaptures a rear area behind a vehicle and generates a first video image.The controller synthesizes a guide wall image that indicates a predictedpath of the vehicle in a display region of the first video image.

An image processing apparatus according to an embodiment of the presentdisclosure includes a communication interface and a controller. Thecommunication interface acquires a first video image capturing a reararea behind a vehicle. The controller synthesizes a guide wall imagethat indicates a predicted path of the vehicle in a display region ofthe first video image.

A display system according to an embodiment of the present disclosureincludes an image sensor, a controller, and a display apparatus. Theimage sensor captures a rear area behind a vehicle and generates a firstvideo image. The controller synthesizes a guide wall image thatindicates a predicted path of the vehicle in a display region of thefirst video image. The display apparatus displays a video image of thedisplay region in which the guide wall image is synthesized.

A vehicle according to an embodiment of the present disclosure includesa display system. The display system includes an image sensor, acontroller, and a display apparatus. The image sensor captures a reararea behind the vehicle and generates a first video image. Thecontroller synthesizes a guide wall image that indicates a predictedpath of the vehicle in a display region of the first video image. Thedisplay apparatus displays a video image of the display region in whichthe guide wall image is synthesized.

An imaging apparatus according to an embodiment of the presentdisclosure includes an image sensor and a controller. The image sensorcaptures a rear area behind a vehicle and generates a first video image.The controller generates a synthesized image by sequentiallysuperimposing a first image and a second image on a display region ofthe first video image. The second image includes a guide wall image thatindicates a predicted path of the vehicle. The first image includes afirst semitransparent image in which a transmittance increases in anupward direction in the display region overlapping with the guide wallimage.

An image processing apparatus according to an embodiment of the presentdisclosure includes a communication interface and a controller. Thecommunication interface acquires a first video image capturing a reararea behind a vehicle. The controller generates a synthesized image bysequentially superimposing a first image and a second image on a displayregion of the first video image. The second image includes a guide wallimage that indicates a predicted path of the vehicle. The first imageincludes a transmittance gradation image in which a transmittanceincreases in an upward direction in the display region overlapping withthe guide wall image.

A display system according to an embodiment of the present disclosureincludes a controller and a display apparatus. The controller generatesa synthesized image by sequentially superimposing a first image and asecond image on a display region of a first video image. The displayapparatus displays the synthesized image. The first image includes atransmittance gradation image in which a transmittance increases in anupward direction in the display region overlapping with the guide wallimage.

A vehicle according to an embodiment of the present disclosure includesa display system. The display system includes an image sensor, acontroller, and a display apparatus. The image sensor captures a reararea behind a vehicle and generates a first video image. The controllergenerates a synthesized image by sequentially superimposing a firstimage and a second image on a display region of the first video image.The display apparatus displays the synthesized image. The second imageincludes a guide wall image that indicates a predicted path of thevehicle. The first image includes a transmittance gradation image inwhich a transmittance increases in an upward direction in the displayregion overlapping with the guide wall image.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a block diagram schematically illustrating a configuration ofa display system according to an embodiment of the present disclosure;

FIG. 2 is a diagram illustrating a vehicle having the display systemmounted thereon viewed from a left side;

FIG. 3A is a diagram schematically illustrating an example of theexterior of the display apparatus of FIG. 1;

FIG. 3B is a diagram schematically illustrating an example of theexterior of the display apparatus of FIG. 1;

FIG. 3C is a diagram schematically illustrating an example of theexterior of the display apparatus of FIG. 1;

FIG. 3D is a diagram schematically illustrating an example of theexterior of the display apparatus of FIG. 1;

FIG. 3E is a diagram schematically illustrating an example of theexterior of the display apparatus of FIG. 1;

FIG. 4 is a diagram illustrating a first example of a first video image;

FIG. 5 is a diagram illustrating a first example of a second video imagecorresponding to a display region of the first video image of FIG. 4;

FIG. 6 is a diagram illustrating an example of a third marker to besuperimposed on a detection object;

FIG. 7 is a diagram illustrating a first example of a first marker and asecond marker displayed in the vicinity of the detection object;

FIG. 8 is a diagram illustrating a second example of the first markerand the second marker displayed in the vicinity of the detection object;

FIG. 9 is a diagram illustrating a third example of the first marker andthe second marker displayed in the vicinity of the detection object;

FIG. 10 is a diagram illustrating a second example of the first videoimage;

FIG. 11 is a diagram illustrating a second example of the second videoimage corresponding to a display region of the first video image of FIG.10;

FIG. 12 is a diagram illustrating a third example of the first videoimage;

FIG. 13 is a diagram illustrating a third example of the second videoimage corresponding to a display region of the first video image of FIG.12;

FIG. 14 is a diagram illustrating a fourth example of the first image;

FIG. 15 is a diagram illustrating a fourth example of the second videoimage corresponding to a display region of the first video image of FIG.14;

FIG. 16 is a diagram illustrating a fifth example of the first videoimage;

FIG. 17 is a diagram illustrating a fifth example of the second videoimage corresponding to a display region of the first video image of FIG.16;

FIG. 18 is a diagram illustrating another example of the second videoimage corresponding to the display region of the first image of FIG. 16;

FIG. 19 is a diagram illustrating a sixth example of the first videoimage;

FIG. 20 is a diagram illustrating a sixth example of the second videoimage corresponding to a display region of the first video image of FIG.19;

FIG. 21 is a diagram illustrating another example of the second videoimage;

FIG. 22 is a diagram illustrating a first example variation of the sixthexample of the second video image;

FIG. 23 is a diagram illustrating a second example variation of thesixth example of the second video image;

FIG. 24 is a diagram illustrating a third example variation of the sixthexample of the second video image;

FIG. 25 is a diagram illustrating a seventh example of the first videoimage;

FIG. 26 is a diagram illustrating a seventh example of the second videoimage corresponding to a display region of the first video image of FIG.25;

FIG. 27 is a diagram illustrating an eighth example of the first videoimage;

FIG. 28 is a diagram illustrating a positional relationship between avehicle and a detection object;

FIG. 29 is a diagram illustrating an eighth example of the second videoimage corresponding to a display region of a first video image of FIG.24;

FIG. 30 is a diagram illustrating an example variation of the eighthexample of the second video image;

FIG. 31 is a diagram illustrating an example in which a display regionof FIG. 30 is changed into a Wide View Display; and

FIG. 32 is a diagram illustrating another example of the second videoimage.

DETAILED DESCRIPTION

It is desirable to improve the convenience of technologies fordisplaying a video image of an outside area of a moving body in an imageprocessing apparatus, an imaging apparatus, a display system, and avehicle. Hereinafter, an embodiment of the present disclosure will bedescribed with reference to the accompanying drawings.

Display System

A display system 10 according to the embodiment of the presentdisclosure will be described with reference to FIG. 1.

As illustrated in FIG. 1, the display system 10 includes an imagingapparatus 20, an image processing apparatus 30, and a display apparatus40. Each constituent element of the imaging apparatus 20 and the displaysystem 10 can transmit and receive information via, for example, anetwork 51. The network 51 may include, for example, wirelesscommunication, wired communication, or a CAN (Controller Area Network).

In some embodiments, some or all of the constituent elements of thedisplay system 10 may be integrally formed as one apparatus. Forexample, the image processing apparatus 30 may be incorporated in theimaging apparatus 20 or the display apparatus 40.

As illustrated in FIG. 2, the imaging apparatus 20, the image processingapparatus 30, and the display apparatus 40 may be provided to a movingbody 50. The term “moving body” as used herein encompasses, for example,vehicles, watercraft, and aircraft. Vehicles include, for example,automobiles, industrial vehicles, rail vehicles, domestic vehicles, andfixed-wing aircraft that travel on a runway. Automobiles may include,for example, cars, trucks, buses, motorcycles, and trolley buses.Industrial vehicles include, for example, agricultural vehicles andconstruction vehicles. Industrial vehicles for industrial purposesinclude, for example, forklifts and golf carts. Industrial vehicles foragricultural purpose include, for example, tractors, tillers,transplanters, binders, combine harvesters, and lawn mowers. Industrialvehicles for construction purposes include, for example, bulldozers,scrapers, excavators, crane trucks, dump trucks, and load rollers.Vehicles may include those that travel on human power. Vehicleclassifications are not limited to the above examples. For example,vehicles may include industrial vehicles authorized to travel on theroad. The same type of vehicle may be included in a plurality ofcategories. Watercraft may include, for example, jetboats, motorboats,and tankers. Aircraft may include, for example, fixed-wing aircraft androtorcraft.

The imaging apparatus 20 can capture an outside area of the moving body50. The imaging apparatus 20 may be disposed at any position inside oroutside of the moving body 50. For example, the imaging apparatus 20 ispositioned in a rear portion of the moving body 50 as illustrated inFIG. 2 to be able to capture an outside area behind the moving body 50.The image processing apparatus 30 may be disposed at any position in themoving body 50. The display apparatus 40 can be viewed by a subject 60.The display apparatus 40 may be disposed in any position in the movingbody 50. For example, the display apparatus 40 is disposed in adashboard of the moving body 50 as illustrated in FIG. 2.

Imaging Apparatus

The imaging apparatus 20 will be described in detail. The imagingapparatus 20 includes an imaging optical system 21, an image sensor 22,a communication interface 23, and a controller 24, as illustrated inFIG. 1 by way of example.

The imaging optical system 21 forms a subject image. For example, theimaging optical system 21 may include an aperture and one or morelenses.

The image sensor 22 includes a plurality of pixels arranged in atwo-dimensional manner. The image sensor 22 may include, for example, aCCD (Charge Coupled Device) image sensor or a CMOS (Complementary MetalOxide Semiconductor) image sensor. The image sensor 22 can capture asubject image formed by the imaging optical system 21 and generate acaptured image.

The communication interface 23 may include a communication interfacecapable of communicating with an external apparatus. The communicationinterface 23 may be capable of transmitting and receiving informationvia the network 51. The external apparatus may include, for example, theimage processing apparatus 30. The term “communication interface” asused herein may include, for example, a physical connector or a wirelesscommunication device. The physical connector may include an electricalconnector which supports transmission of electrical signals, an opticalconnector which supports transmission of optical signals, or anelectromagnetic connector which supports transmission of electromagneticwaves. The electrical connector may be a connector conforming toIEC60603, a connector conforming to the USB standard, a connectorcompatible with an RCA connector, a connector compatible with anS-terminal defined by EIAJ CP-1211A, a connector compatible with aD-terminal defined in EIAJ RC-5237, a connector conforming to the HDMI®(HDMI is a registered trademark in Japan, other countries, or both)standard, or a connector compatible with a coaxial cable including BNC(British Naval connector, Baby-series N connector, or the like). Theoptical connector may include a variety of connectors conforming to IEC61754. The wireless communication device may include those conforming toBluetooth® (Bluetooth is a registered trademark in Japan, othercountries, or both) or standards including IEEE802.11. The wirelesscommunication device includes at least one antenna.

The controller 24 includes at least one processor. The term “processor”as used herein may include a specialized processor dedicated to specificprocessing or a general-purpose processor configured to perform aspecific function by reading a specific program. The specializedprocessor may include a DSP (Digital Signal Processor) or an ASIC(Application Specific Integrated Circuit). The processor may include aPLD (Programmable Logic Device). The PLD may include an FPGA(Field-Programmable Gate Array). The controller 24 may be one of a SoC(System-on-a-Chip) and a SiP (System In a Package) in which one or moreprocessors cooperate with one another.

The controller 24 is configured to control overall operation of theimaging apparatus 20. The controller 24 may cause the image sensor 22 togenerate captured images at any frame rate. The frame rate mayapproximately correspond to, for example, a frame rate at which imagescan be displayed on the display apparatus 40. The controller 24 mayperform predetermined image processing on the captured image. The imageprocessing may include, for example, exposure adjustment, whitebalancing, distortion correction, and the like. The controller 24outputs the captured image to the image processing apparatus 30 via thecommunication interface 23. For example, the controller 24 maysequentially output captured images at the frame rate described above.Hereinafter, each captured image output at the frame rate describedabove will also be simply referred to as a frame. A plurality ofcaptured images output from the imaging apparatus 20 will also bereferred to as first video images. For example, when the frame rate is60 fps (Flame per Seconds), sixty images captured each second are outputas the first video images.

Image Processing Apparatus

The image processing apparatus 30 will be described in detail. The imageprocessing apparatus 30 includes a communication interface 31, a memory32, and a controller 33.

The communication interface 31 may include a communication interfacecapable of communicating with various external apparatuses. The externalapparatuses may include, for example, the imaging apparatus 20, thedisplay apparatus 40, an ECU (Electronic Control Unit or Engine ControlUnit) provided to the moving body 50, a speed sensor, an accelerationsensor, a rotation angle sensor, a steering angle sensor, an enginespeed sensor, an accelerator sensor, a brake sensor, an illuminationsensor, a raindrop sensor, a travel distance sensor, an obstacledetection device using a millimeter wave radar, an ultrasonic sonar orthe like, an ETC (Electronic Toll Collection system) receivingapparatus, a GPS (Global Positioning System) apparatus, a navigationapparatus, an Internet server, a cellular phone, and the like.

The communication interface 31 may include a communication interface forpedestrian-vehicle communication, road-vehicle communication, andinter-vehicle communication. The communication interface 31 may includea receiver which is compatible with a light beacon for DSRC (DedicatedShort-Range Communication: a narrowband communication system) or VICS®(Vehicle Information and Communication System: VICS is a registeredtrademark in Japan, other countries, or both) provided in Japan. Thecommunication interface 31 may include a receiver which is compatiblewith the road traffic information providing systems of other countries.

The communication interface 31 may be capable of acquiring variousinformation from the external apparatuses. For example, thecommunication interface 31 may be capable of acquiring moving bodyinformation and environmental information.

The moving body information may include any information associated withthe moving body 50. For example, the moving body information mayinclude, with respect to the moving body 50, a speed, an acceleration, aturning gravity, an inclination, a direction, a turning status, asteering angle of the steering wheel, the temperature of the coolingwater, a fuel remaining amount, a battery remaining amount, a batteryvoltage, an engine speed, a gear position, presence or absence of areverse signal, the presence or absence of accelerator operation, anaccelerator position, the presence or absence of brake operation, thebrake pedal pressing degree, the presence or absence of parking brakeoperation, a rotational speed difference between the front and rearwheels or 4 wheels, tire pressure, an expansion and contraction amountof the damper, the spatial position of the eyes of the driver, thenumber of passengers and seat positions, seat belt fasteninginformation, opening and closing of the doors, opening and closing ofthe windows, interior temperature, the presence or absence of operationof the air conditioning, air-conditioning setting temperature, anair-conditioning air volume, outside air circulation setting, anoperating condition of the wiper, a driving mode, information aboutconnection to an external device, current time, average fuelconsumption, current fuel consumption, lighting states of various lamps,positional information, and route information to a destination. Thevarious lamps may include, for example, headlamps, fog lamps, reversinglamps, position lamps, and indicator lamps.

The environmental information may include any information about theenvironment outside of the moving body 50. The environmental informationmay include, for example, brightness around the moving body 50, theweather, air pressure, outside air temperature, map information, trafficinformation, road construction information, temporary change of thespeed limit of the road, objects detected by other vehicles, andlighting states of traffic signals.

The memory 32 may include a temporary storage device and a secondarystorage device. The memory 32 may include, for example, a semiconductormemory, a magnetic memory, or an optical memory. The semiconductormemory may include a volatile memory or a nonvolatile memory. Themagnetic memory may include, for example, a hard disk or a magnetictape. The optical memory may include, for example, a CD (Compact Disc),a DVD (Digital Versatile Disc), and BD® (Blu-ray Disc®); BD and Blu-rayare registered trademarks in Japan, other countries, or both). Thememory 32 stores various information and programs necessary for theoperation of the image processing apparatus 30.

The controller 33 includes one or more processors. The controller 33controls overall operations of the image processing apparatus 30.

The controller 33 may acquire the moving body information and theenvironmental information from an external apparatus via thecommunication interface 31. The controller 33 may determine a predictedpath of the moving body 50 on the basis of, for example, the moving bodyinformation. Hereinafter, the predicted path of the moving body 50 willalso be referred to as a first predicted path.

The controller 33 may acquire the first video images from the imagingapparatus 20 via the communication interface 31. The first video imagesinclude a detection region and a display region.

The controller 33 may detect at least a portion of a detection object inthe detection region of the acquired first video images. The detectionregion of the first video images may be at least a portion of a capturedimage for each frame of the first video images. Each frame of the firstvideo images may be referred to as a captured image. The detectionregion of the first video images may be larger than the display region.The detection region of the first video images may encompass the displayregion. The controller 33 can detect the detection object located insideof the display region. The controller 33 can detect the detection objectlocated outside of the display region and inside of the detectionregion. A region inside of the detection region and the display regionmay be referred to as a first region. A region inside of the detectionregion and outside of the display region may be referred to as a secondregion.

The detection object may include a plurality of types of objects. Thetypes of objects may include, for example, a person, another movingbody, a road, a lane, a white line, a gutter, a sidewalk, a pedestriancrossing, a road sign, a traffic sign, a guardrail, a wall, and atraffic signal. The types of objects detectable by the controller 33 arenot limited these examples. In a case where a portion of the detectionobject is concealed behind another body in the first video images, thedetection object may include at least a portion that is not concealedbehind the body. For example, when the lower body of a pedestrian isconcealed behind an obstacle in the first video images, the controller33 may detect the upper body of the pedestrian. Any appropriate objectdetection algorithms may be employed for the detection of at least aportion of the detection object. For example, the controller 33 maydetect at least a portion of the detection object by employing algorithmsuch as pattern matching feature point extraction using the capturedimage for each frame of the first video images.

When the controller 33 detects at least a portion of the detectionobject in the first video images, the controller 33 may determine apredicted path of the detection object on the basis of the first videoimages. Hereinafter, the predicted path of the detection object willalso be referred to as a second predicted path. Any appropriatealgorithm may be employed for the determination of the second predictedpath. For example, the controller 33 may determine the second predictedpath on the basis of changes in the orientation and position of thedetection object in the captured image for each frame of the first videoimages.

When the controller 33 detects at least a portion of the detectionobject in the first video images, the controller 33 may estimate arelative positional relationship between the moving body 50 and thedetection object on the basis of the first video images. The relativepositional relationship may include, for example, a distance between themoving body 50 and the detection object, or whether the first predictedpath of the moving body 50 and the second predicted path of thedetection object overlap with each other. Any appropriate algorithm maybe employed for the estimation of the distance between the moving body50 and the detection object. For example, the controller 33 may estimatethe distance between the moving body 50 and the detection object byemploying a motion stereo method using the captured image for each frameof the first video images signal. In some embodiments, the controller 33may acquire information indicating the relative positional relationshipbetween the moving body 50 and the detection object from an externalapparatus via the communication interface 31.

When the distance between the moving body 50 and the detection objectdecreases, the controller 33 may determine which one of the moving body50 and the detection object contributes more to the decrease indistance. Any appropriate algorithm may be employed to determine therespective contributions of the moving body 50 and the detection objectwith respect to the decrease in distance. In one example, the controller33 may detect a moving speed of the moving body 50 on the basis of themoving body information. The controller 33 may detect a moving speed ofthe detection object on the basis of, for example, a positional changeof the detection object in the captured image for each frame of thefirst video images. The controller 33 may determine that one of themoving body 50 and the detection object that has a greater moving speedcontributes more to the decrease in distance. In another example, whenthe moving speed of the moving body 50 is smaller than a referencevalue, the controller 33 may determine that the detection objectcontributes more to the decrease in distance. When the moving speed ofthe moving body 50 is equal to or larger than the reference value, thecontroller 33 may determine that the moving body 50 contributes more tothe decrease in distance. The reference value may be set appropriately,and may for example be set to approximately zero. Operation of the imageprocessing apparatus 30 on the basis of the respective contributions ofthe moving body 50 and the detection object with respect to the decreasein distance will be described in detail later.

When at least a portion of the detection object is detected in the firstvideo images, the controller 33 may determine on the basis of the firstvideo images whether there is a possibility of contact between themoving body 50 and the detection object. Any appropriate algorithm maybe employed to determine the possibility of contact between the movingbody 50 and the detection object. For example, when at least one of acondition specifying that the distance between the moving body 50 andthe detection object is smaller than a predetermined threshold and acondition specifying that a rate at which the distance is decreasing isequal to or greater than a predetermined threshold is met, thecontroller 33 may determine that there is a possibility of contactbetween the moving body 50 and the detection object. Operation of theimage processing apparatus 30 in accordance with the presence or absenceof the possibility will be described in detail later.

The controller 33 may cause second video images corresponding to thedisplay region of the first video images acquired from the imagingapparatus 20 to be displayed on the display apparatus 40. In particular,the controller 33 may output the second video images to the displayapparatus 40 via the communication interface 31. For example, when thecontroller 33 detects a rearward movement of the moving body 50 on thebasis of the moving body information, the controller 33 may cause thesecond video images to be displayed on the display apparatus 40. Forexample, the controller 33 may detect the rearward movement on the basisof a shift position of the transmission gear. For example, thecontroller 33 may detect the rearward movement on the basis of a reversesignal output from the moving body at the time of a rearward movement.The second video images may include, for example, a video imageextracted from the display region of the captured image for each frameof the first video images. The display region of the first video imagesmay be at least a region of the captured image for each frame of thefirst video images. The display region may be smaller than the detectionregion. The display region may be encompassed within the detectionregion. A position, a shape, and a size of the display region may bedetermined appropriately. The controller 33 may change the position, theshape, and the size of the display region. The position, the shape, andthe size of the display region may be changed to substantially match thedetection region.

The controller 33 may cause various markers in combination with thesecond video images to be displayed on the display apparatus 40. Amethod for such combining includes overwriting or mixing. The marker mayinclude, for example, one or more images. The controller 33 maydynamically change a display mode of at least a portion of the markersuperimposed on the second video images. The display mode may include,for example, a position, a size, a shape, a color, or a shading of atleast a portion of a marker in the second video images. When thecontroller 33 displays a marker corresponding to the detection objectdetected in the first video images, the controller 33 may determine thedisplay mode of the marker in accordance with the type of the marker.The operation of the image processing apparatus 30 for causing variousmarkers to be displayed on the display apparatus 40 will be described indetail later.

Display Apparatus

The display apparatus 40 will be described in detail. The displayapparatus 40 may include, for example, a liquid crystal display or anorganic EL (Electro-Luminescence) display. The display apparatus 40 maydisplay, for example, the second video images input from the imageprocessing apparatus 30 via the network 51. The display apparatus 40 mayfunction as a touchscreen capable of receiving user operations. Thedisplay apparatus 40 may include a switch or a key capable of receivinga user operation. The switch may include a mechanical switch or anelectronic switch. The key may include a mechanical key or an electronickey. When the display apparatus 40 receives a user operation, thedisplay apparatus 40 may transmit a user input corresponding to the useroperation to the image processing apparatus 30.

The display apparatus 40 may be arranged at various locations of themoving body 50. FIG. 3A to FIG. 3E illustrate example arrangement of thedisplay apparatus 40. FIG. 3A illustrates a display apparatus 40 a of anin-dashboard type arranged in the dashboard of the vehicle. FIG. 3Billustrates a display apparatus 40 b of an on-dashboard type arranged onthe dashboard. In FIG. 3B, the display apparatus 40 b is incorporated inthe moving body 50. The display apparatus 40 b may be detachablyattached on the dashboard. FIG. 3C illustrates a display apparatus 40 cthat is built into a room mirror and capable of displaying a video imageas necessary. FIG. 3D illustrates a display apparatus 40 d built in aninstrumental panel. In FIG. 3D, the display apparatus 40 d is arrangedadjacent to the instruments such as a speedometer and a tachometer. Inone embodiment, the display apparatus 40 d may be configured as an LCDor the like and may constitute the entire instrumental panel thatdisplay a second video image together with images of the speedometer andthe tachometer. FIG. 3E illustrates a display apparatus 40 e that isconfigured as a mobile information terminal such as a tablet computer.The display apparatus 40 e may be configured as a mobile phone display.

The second video images and the various markers displayed on the displayapparatus 40 under the control of the image processing apparatus 30 willbe described in detail with reference to FIG. 4 to FIG. 18. According tothe present disclosure, the terms “up-down direction” and “left-rightdirection” in a video image or an image correspond to thetwo-dimensional directions in the video image or the image. According tothe present disclosure, the terms “height direction”, “horizontaldirection”, and “depth direction” in a video image or an imagecorrespond to the three-dimensional directions in the space captured inthe video image or the image.

First Example (Reference Example)

FIG. 4 illustrates a first example of a detection region 61 of a firstvideo image acquired by the image processing apparatus 30 from theimaging apparatus 20. In the example illustrated in FIG. 4, thedetection region 61 is longer in the left-right direction than theup-down direction. The display region 62 is positioned in the center ofthe detection region 61 with respect to the left-right direction. Thecontroller 33 may detect each of a pedestrian 63 and a vehicle 64captured in the display region 62 of the first video image as adetection object.

The controller 33 determines whether one or more conditions are met onthe basis of a relative positional relationship between a detectionobject detected within the display region 62 of the first video imageand the moving body 50. The one or more conditions may include, forexample, a first condition specifying that the detection object islocated on the first predicted path 65 of the moving body 50. The one ormore conditions may include, for example, a second condition specifyingthat at least a portion of the first predicted path 65 of the movingbody 50 and at least a portion of the second predicted path of thedetection object overlap with each other. When the controller 33determines that one or more of the conditions are met, the controller 33may cause a predetermined marker corresponding to the detection objectto be superimposed on the second video images and displayed on thedisplay apparatus 40. The predetermined marker may include a firstmarker, a second marker, or a third marker.

In the first example, the controller 33 may determine that the one ormore conditions are met with respect to the pedestrian 63. In this case,the controller 33 may display a marker corresponding to the pedestrian63. The controller 33 may determine that the one or more conditions arenot met with respect to the vehicle 64. In this case, the controller 33does not display the marker corresponding to the vehicle 64.

FIG. 5 illustrates an example of a second video image corresponding tothe display region 62 of the first video image illustrated in FIG. 4.When an aspect ratio of the display region 62 of the first video imagediffers from an aspect ratio of the screen of the display apparatus 40,the controller 33 may output the second video image obtained by cuttingout the display region 62 of the first video image and modifying thedisplay region 62 in accordance with the aspect ratio of the screen ofthe display apparatus 40. The second video image includes the pedestrian63 and the vehicle 64 as illustrated in FIG. 5.

The controller 33 may cause guide lines 66 which indicate at least aportion of the first predicted path 65 of the moving body 50 illustratedin FIG. 4 by way of example to be superimposed on the second video imageand displayed on the display apparatus 40. The controller 33 maydynamically change the guide lines 66 on the basis of, for example, achange of the steering angle of the steering wheel.

An area of the first video image is wider than the display region 62.The controller 33 may change the area of the display region 62. Thecontroller 33 may cause an icon image 67 to be superimposed on thesecond video image and displayed on the display apparatus 40. Forexample, an outline 67 a of the icon image 67 illustrated in FIG. 4corresponds to a maximum area of the display region 62 when the area ofthe display region 62 is changed. A white rectangle 67 b of the iconimage 67 corresponds to the display region 62. The icon image 67illustrated in FIG. 4 indicates a position and a size of the displayregion 62 relative to the maximum area of the display region 62.

FIG. 6 illustrates an example of a marker to be superimposed on thepedestrian 63 in the second video image. Hereinafter, this marker willalso be referred to as a third marker 68. An outline 69 of the thirdmarker 68 may substantially match the outline of the pedestrian 63detected in the second video image. A region 70 within the outline 69 ofthe third marker 68 may be filled with a color or pattern correspondingto the type of the detection object, e.g., “person”. When the pedestrian63 is detected in the first video image, the controller 33 may cause thethird marker 68 to be superimposed on the pedestrian 63 in the secondvideo image and displayed on the display apparatus 40. Thisconfiguration enables the subject 60 to easily view the pedestrian 63 inthe second video image. The controller 33 may hide the third marker 68when a predetermined time has elapsed after the third marker 68 isdisplayed.

FIG. 7 illustrates examples of two types of markers superimposed in thevicinity of the pedestrian 63 in the second video image. Hereinafter,each of the two types of markers will also be referred to as a firstmarker 71 and a second marker 72. For example, the controller 33 maycause the first marker 71 and the second marker 72 to be superimposed onthe second video image and displayed on the display apparatus 40 afterhiding the third marker 68.

The controller 33 may move a position of the first marker 71 followingthe pedestrian 63 in the second video image. The subject 60 may easilyrecognize the pedestrian 63 because the first marker 71 follows thepedestrian 63. The first marker 71 is displayed in the vicinity of thepedestrian 63 in a manner spaced apart therefrom. The subject 60 mayeasily recognize the behavior of the pedestrian 63 when the first marker71 is displayed on the display apparatus 40. The controller 33 maychange a superimposing position of the second marker 72 relative to asuperimposing position of the first marker 71 in the second video image.The controller 33 may move the second marker 72 relative to the positionof the first marker 71 serving as a reference.

For example, when the distance between the moving body 50 and thepedestrian 63 decreases, the controller 33 may determine that the movingbody 50 contributes more to the decrease in distance. In this case, thecontroller 33 may move the second marker 72 toward the first marker 71.First, the controller 33 displays the second marker 72 in a positiondistanced from the first marker 71. Subsequently, the controller 33moves the second marker 72 toward the first marker 71 until the distancetherebetween reaches a predetermined distance. Next, the controller 33hides the second marker 72. Then, the controller 33 displays the secondmarker 72 in a position distanced from the first marker 71 and repeatsthe operation described above. In this example, the second marker 72approaches the first marker 71 displayed as an object. Thus, the subject60 can recognize that the second marker 72 is approaching the firstmarker 71.

For example, when the distance between the moving body 50 and thepedestrian 63 decreases, the controller 33 may determine that thepedestrian 63 contributes more to the decrease in the distance. In thiscase, the controller 33 may move the second marker 72 away from thefirst marker 71. First, the controller 33 displays the second marker 72in the vicinity of the first marker 71. Subsequently, the controller 33moves the second marker 72 away from the first marker 71 until thedistance therebetween reaches a predetermined distance. Next, thecontroller 33 hides the second marker 72. Then, the controller 33displays the second marker 72 in the vicinity of the first marker 71 andrepeats the operation described above. In this example, the secondmarker 72 is moving away from the first marker 71 displayed as theobject. Thus, the subject 60 can recognize that the second marker 72 ismoving away from the first marker 71.

The controller 33 changes a moving direction of the second marker 72relative to the first marker 71 on the basis of the respectivecontributions of the moving body 50 and the pedestrian 63 with respectto the decrease in distance between the moving body 50 and thepedestrian 63. For example, the subject 60 can recognize whether themoving body 50 is approaching the pedestrian 63 or whether thepedestrian 63 is approaching the moving body 50, on the basis of themoving direction of the second marker 72.

The controller 33 may repeatedly expand and contract the second marker72 centered on the first marker 71 in the second video image asillustrated in FIG. 8 by way of example. The controller 33 maysuperimpose the first marker 71 or the second marker 72 having the sameshape as the outline 69 of the pedestrian 63 in the second video imageas illustrated in FIG. 9 by way of example. The controller 33 mayrepeatedly expand or contract the second marker 72 centered on the firstmarker 71. The controller 33 changes between expansion and contractionof the second marker 72 in accordance with the respective contributionsof the moving body 50 and the pedestrian 63 with respect to the decreasein distance between the moving body 50 and the pedestrian 63.

When the distance between the detection object and the moving body 50represented by the first marker 71 and the second marker 72,respectively, becomes smaller than a predetermined threshold, thecontroller 33 may superimpose another marker on the second video image.Hereinafter, the another marker will also be referred to as a fourthmarker. The fourth maker may include any appropriate image. For example,the fourth marker may include an image showing an exclamation mark “!”.In this configuration, for example, when the pedestrian 63 and themoving body 50 represented by the first marker 71 and the second marker72, respectively, become close to each other and have a certain distanceor less therebetween, the fourth marker is superimposed on the secondvideo image and displayed. The fourth marker enables recognition that,for example, the pedestrian 63 is positioned in the vicinity of themoving body 50. In some embodiments, the controller 33 may changedisplay modes of the first marker 71 and the second marker 72 when thedistance between the detection object and the moving body 50 representedby the first marker 71 and the second marker 72, respectively, fallsbelow the predetermined threshold. For example, the controller 33 maychange the colors of the first marker 71 and the second marker 72. Thisconfiguration for changing the colors of the markers enables the subject60 to recognize that, for example, the pedestrian 63 is positioned inthe vicinity of the moving body 50.

The controller 33 can detect two detection objects located one behindthe other in the depth direction. The controller 33 may display thefirst marker 71 and the second marker 72 representing the respective twodetection objects located one behind the other. The controller 33 maydisplay the first marker 71 and second marker 72 in differentappearances together with the two detection objects. For example, thecontroller 33 may display the first marker 71 and the second marker 72of a first detection object located on the rear side in an inconspicuousmanner as compared to the first marker 71 and the second marker 72 of asecond detection object located on the front side. For example, thecontroller 33 may change characteristics of the first marker 71 and thesecond marker 72 of the first detection object located on the rear sidein the depth direction such that they are dark in color and have a hightransmittances and thin lines as compared to the first marker 71 and thesecond marker 72 of the second detection object located on the frontside.

Second to Fourth Examples (Reference Examples)

FIG. 10 illustrates a second example of the detection region 61 of thefirst video image acquired from the imaging apparatus 20 by the imageprocessing apparatus 30. In the example illustrated in FIG. 10, thedetection region 61 is longer in the left-right direction than theup-down direction. The display region 62 is positioned at the center inthe left-right direction of the detection region 61. The controller 33may detect each of the pedestrian 63 a located inside of the displayregion 62 of the first video image and the pedestrians 63 b and 63 clocated inside of the detection region 61 and outside of the displayregion 62 as a detection object. The controller 33 performs the sameprocessing on the pedestrian 63 a as the processing performed on thepedestrian 63 as illustrated in FIG. 4 by way of example.

When a detection position of the detection object in the first videoimage is outside of the display region 62 and, simultaneously, inside ofthe detection region 61, the controller 33 may cause a markercorresponding to the detection object to be superimposed on the secondvideo image and displayed on the display apparatus 40. Hereinafter, thismarker will also be referred to as a fifth marker. When the controller33 determines that there is a possibility of contact between the movingbody 50 and the detection object, the controller 33 may display thefifth marker. When the detection position of the detection object in thefirst video image is located on the right side of the display region 62,the controller 33 may cause the fifth marker to be superimposed on theright-side edge region of the second video images and displayed on thedisplay apparatus 40. When the detection position of the detectionobject in the first video image is located on the left side of thedisplay region 62, the controller 33 may cause the fifth marker to besuperimposed on the left-side edge region of the second video image anddisplayed on the display apparatus 40.

In the second example, a detection position of the pedestrian 63 b islocated on the right side of the display region 62. The controller 33may determine that there is a possibility of contact between the movingbody 50 and the pedestrian 63 b. In this case, the controller 33 maycause the fifth marker corresponding to the pedestrian 63 b to besuperimposed on the right-side edge region of the second video image anddisplayed in the display apparatus 40. The fifth marker corresponding tothe pedestrian 63 b will be described in detail later. The detectionposition of the pedestrian 63 c is on the left side of the displayregion 62. The controller 33 may determine that there is no possibilityof contact between the moving body 50 and the pedestrian 63 c. In thiscase, the controller 33 does not need to display the fifth markercorresponding to the pedestrian 63 c.

FIG. 11 illustrates an example of the second video image correspondingto the display region 62 of the first video image illustrated in FIG.10. As illustrated in FIG. 11, the pedestrian 63 a is displayed in thesecond video image. The pedestrians 63 b and 63 c are not displayed inthe second video image.

The controller 33 may cause, for example, an obstacle image 74 to besuperimposed on the second video images and displayed on the displayapparatus 40 as illustrated in FIG. 11. The obstacle image 74 indicatesa detection result of an obstacle detection apparatus provided to themoving body 50 that uses ultrasonic sonar or the like. The obstacleimage 74 may include an image 74 a, an image 74 b, and an image 74 c.The image 74 a is an image of the moving body 50 viewed from above. Theimage 74 b is an image indicating that an obstacle is detected on theleft rear side of the moving body 50. The image 74 c is an imageindicating that an obstacle is detected on the right rear side of themoving body 50. The detection result of the obstacle detection apparatusand a detection result of the detection object of the controller 33 maynot necessarily coincide. In the example illustrated in FIG. 11, forexample, the obstacle image 74 indicates that obstacles are detected onboth the right rear side and the left rear side of the moving body 50.On the other hand, the controller 33 may determine that there is nopossibility of contact between the moving body 50 and the pedestrian 63c on the left rear side of the moving body 50. In this case, thecontroller 33 does not need to display the fifth marker corresponding tothe pedestrian 63 c.

FIG. 11 illustrates an example of a fifth marker 73 corresponding to thepedestrian 63 b. The fifth marker 73 may include an icon image 73 a anda band image 73 b. The icon image 73 a may be an image corresponding toa “person” as the type of the detection object. The icon image 73 aenables the subject 60 to recognize that there is a person on the rightside of the second video image. The band image 73 b is, for example, animage of a band that extends in the up-down direction in the secondvideo image. The band image 73 b may be filled with color or a patterncorresponding to the “person” as the type of the detection object. Thecontroller 33 may move the band image 73 b within a right-side edgeregion 73 c of the second video image. The controller 33 may change amoving speed and a width of the band image 73 b.

The fifth marker 73 will be described in detail. The controller 33 maydetermine the width of the band image 73 b on the basis of the distancebetween the moving body 50 and the pedestrian 73 b. For example, thecontroller 33 b may increase the width of the band image 73 b as thedistance becomes smaller. The band image 73 b enables the subject 60 torecognize the distance between the moving body 50 and the pedestrian 63b on the basis of the width of the band image 73 b.

The controller 33 may determine that the moving body 50 contributes moreto the reduction of the distance between the moving body 50 and thepedestrian 63 b. In this case, the controller 33 repeatedly moves theband image 73 b in a first direction within the right-side edge region73 c of the second video image. The first direction may be, for example,a direction directing from the outside to the inside in the left-rightdirection of the second video image. The controller 33 may determinethat the pedestrian 63 b contributes more to the reduction of thedistance between the moving body 50 and the pedestrian 63 b. In thiscase, the controller 33 repeatedly moves the band image 73 b in a seconddirection within the right-side edge region 73 c of the second videoimage. The second direction may be, for example, a direction directingfrom the inside to the outside in the left-right direction of the secondvideo image. The band image 73 b enables the subject 60 to know whetherthe moving body 50 is approaching the pedestrian 63 b or the pedestrian63 b is approaching the moving body 50, on the basis of a movingdirection of the band image 73 b.

The controller 33 may determine the moving speed of the band image 73 bon the basis of the rate at which the distance between the moving body50 and the pedestrian 63 b is decreasing. For example, the moving speedof the band image 73 b may be faster as the rate at which the distanceis decreasing is faster. The band image 73 b enables the subject 60 torecognize the rate of decrease of the distance between the moving body50 and the pedestrian 63 b on the basis of the moving speed of the bandimage 73 b.

In a state in which the fifth marker 73 is displayed, when thecontroller 33 detects, for example, a user input corresponding to apredetermined user operation, the controller 33 may change the displayregion 62 to encompass the detection position of the pedestrian 63 b inthe first video image. For example, the controller 33 may extend thedisplay region 62 of the first video image in the left-right directionand shift the display region 62 to the right in the detection region 61as illustrated in FIG. 12. This configuration includes the pedestrian 63b in the second video image as illustrated in FIG. 13 by way of example.

The predetermined user operation described above may include anyappropriate user operation. For example, the predetermined useroperation described above may include a first user operation forchanging a steering angle of the steering wheel of the moving body 50.The fifth marker 73 may function as a GUI (Graphic User Interface)configured to receive a second user operation. Hereinafter, the GUI willalso be referred to as an interface image. In this case, thepredetermined user operation described above may include the second useroperation.

The controller 33 may autonomously change the display region 62 suchthat the detection position of the pedestrian 63 b in the first videoimage is included in the display region 62. In this case, the controller33 may maintain the autonomous change of the display region 62 until thepedestrian 63 b stops being detected in the detection region 61 of thefirst video image.

The controller 33 may change the icon image 67 on the basis of thechange of the display region 62 as illustrated in FIG. 13 by way ofexample.

The controller 33 may change the display region 62 of the first videoimage on the basis of, for example, a pinch-in operation and a pinch-outoperation of the display apparatus 40. For example, the controller 33may substantially match the display region 62 with the detection region61 as illustrated in FIG. 14. In this case, all detection objects in thedetection region 61 are displayed on the display apparatus 40 asillustrated in FIG. 15 by way of example.

Fifth Example (Reference Example)

FIG. 16 illustrates a third example of the detection region 61 of thefirst video image acquired by the image processing apparatus 30 from theimaging apparatus 20. In the example illustrated in FIG. 16, thedetection region 61 is longer in the left-right direction than theup-down direction. The display region 62 is positioned at the center ofthe left-right direction of the detection region 61. The controller 33may detect each of a vehicle 64 a indicated in the first predicted path65 of the moving body 50 and a vehicle 64 b and a pedestrian 63 dindicated outside of the first predicted path 65.

In the fifth example, a case in which the outside area of the movingbody 50 is dark, such as at night or inside a tunnel will be described.When the outside area of the moving body 50 is dark, characteristicvalues of the first video image and the second video image may decrease.The characteristic values may include any parameters associated with thevisibility of the video image. For example, the characteristic valuesmay include at least one of a luminance value and a contrast ratio ofthe video image. The decrease of the characteristic value of the secondvideo images may lead to a deterioration in the visibility of the secondvideo image.

The controller 33 may perform predetermined image processing on a regioncorresponding to the detection object in the second video images. Thepredetermined image processing may include first processing tosuperimpose a marker corresponding to a detection object on the region.Hereinafter, this marker will also be referred to as a sixth marker. Thesixth marker may include, for example, an image substantiallycorresponding to an outline of the detection object in the second videoimages. In this configuration, the sixth marker is superimposed on thedetection object in the second video images. This enables the subject 60to easily recognize the detection object in the second video images evenwhen the characteristic value of the second video images is low. Thespecific image processing may include second processing to change thecharacteristic value of the region corresponding to the detection objectin the second video images. For example, the controller 33 may changethe characteristic value of the region in such a manner so as to improvethe visibility of the region in the second video images. Thisconfiguration improves the visibility of the detection object in thesecond video images. Thus, the subject 60 can easily recognize thedetection object in the second video images even when the characteristicvalue of the second video images is low.

The controller 33 may perform the specific image processing describedabove when one or more conditions are met. The one or more conditionsmay include a condition specifying that the detection object is locatedin the first predicted path 65 of the moving body 50. The one or moreconditions may include a condition specifying that the first predictedpath 65 of the moving body 50 and the second predicted path of thedetection object overlap with each other. The one or more conditions mayinclude a condition specifying that the distance between the moving body50 and the detection object is less than a predetermined threshold. Theone or more conditions may include a condition specifying that thecharacteristic value of at least a portion of the second video images isless than a predetermined threshold.

In the fifth example, the controller 33 may determine that the one ormore conditions described above are met with respect to the vehicles 64a and 64 b and the pedestrian 63 d. In this case, the controller 33 maycause sixth markers 75 a, 75 b, and 75 c corresponding to the vehicles64 a and 64 b and the pedestrian 63 d, respectively, to be superimposedon the second video image and displayed on the display apparatus 40 asillustrated in FIG. 17 by way of example. The controller 33 may displaythe sixth markers on the detection objects in an overlapping manner inbright locations.

The controller 33 may change a shape of the guide lines 66. Thecontroller 33 may change the shape of the guide lines 66 in a regionwhere the guide lines 66 and the detection object overlap with eachother. FIG. 18 illustrates an example of the shape of the guide lines66. The guide lines 66 are not displayed in a region in which the guidelines 66 overlap the sixth marker 75 a in FIG. 18. The shape of theguide lines 66 is not limited to such omission and may accommodate otherdesign changes. Design changes includes changes of color, changes oftransmittance, changes of line type such as a change to a broken line,or changes of line thickness, and flashing. The controller 33 may changethe shape of the guide lines 66 when the sixth marker is not displayed.The controller 33 may change the shape of the guide lines 66 when thefirst marker 71 and the second marker 72 are displayed as the detectionobjects.

According to the display system 10 of the first embodiment as describedabove, a variety of markers corresponding to the detection objectsdetected in the first video image are superimposed on the second videoimage and displayed on the display apparatus 40. This configurationenables the subject 60 to recognize a relative positional relationshipbetween the moving body 50 and the detection objects at a glance. Thus,the convenience of technologies for displaying video images of theoutside area of the moving body 50 is improved.

Examples of various video images that are generated by the imageprocessing apparatus 30 by synthesizing a guide wall image 80 and otherimages on the display region of the first video image and displayed onthe display apparatus 40 will be described in detail below withreference to FIG. 19 to FIG. 31.

Sixth Embodiment

FIG. 19 illustrates a sixth example of the detection region 61 of thefirst video image acquired from the imaging apparatus 20 by the imageprocessing apparatus 30. The imaging apparatus 20 may be arranged insuch a manner as to capture a rear area behind a vehicle as the movingbody 50. In the example illustrated in FIG. 19, the detection region 61is longer in the left-right direction than the up-down direction. Thedisplay region 62 is positioned at the center of the left-rightdirection of the detection region 61. The detection region 61 is notlimited to such a shape longer in the left-right direction than in theup-down direction and may have a variety of shapes including a square, arectangle in portrait orientation, a round shape, and the like. Thedisplay region 62 may be arranged in a variety of positions and have avariety of sizes and shapes. For example, the display region is notlimited to being positioned at the center of the detection region 61 andmay be shifted to the left or right. The display region 62 is notlimited to a portion of the detection region 61 and may cover thedetection region 61 in its entirety. The controller 33 may change thedisplay region 62 of the first video image in accordance with a pinch-inoperation and a pinch-out operation in respect of the display apparatus40.

The controller 33 generates the second image by synthesizing a guidewall image 80 (see FIG. 20) that indicates the first predicted path 65of the moving body 50 in the display region of the first video imagesacquired from the imaging apparatus 20. The controller 33 may outputimages obtained by superimposing the guide wall image 80 on the secondvideo images and cause the display apparatus 40 to display the images.The guide wall image 80 may indicate a predicted path when the movingbody 50 moves rearward. The guide wall image 80 is a marker thatpresents a three-dimensional impression to the subject 60. The guidewall image 80 may be considered to be an image in which a virtual guidewall for guiding to a predicted path arranged in the real space of thefirst video image is mapped on the first video images captured by theimaging apparatus 20. The guide wall image 80 may be visually recognizedas a plurality of virtual translucent wall surfaces that extend from theroad surface to a predetermined height in the height direction withinthe field of view of the subject 60. The guide wall image 80 can beconsidered to be a three-dimensional display of guide lines formed aswalls displayed on the display apparatus 40 when the vehicle movesrearward. The display of the walls may include other modes such assurfaces, films, plates, and the like. The three-dimensional display ofthe guide wall image 80 enables the subject 60 to easily recognize alocation of a parking space on the road, a distance to an obstacle, andthe like.

The controller 33 can recognize a detection object in the display region62 of the first video images. The controller 33 can detect the detectionobject located in the first predicted path 56 in the display region 62of the first video images. When the detection object is detected, thecontroller 33 can synthesize a first recognition wall image 83 as avirtual plane on a detection object side of the moving body 50. Thefirst recognition wall image 83 moves together with the detection objectwhen the detection object moves.

FIG. 20 illustrates an example of a second video image corresponding tothe display region 62 of the first video image illustrated in FIG. 19.The guide wall image 80 is arranged spaced apart upward from the bottomedge of the second video image. The guide wall image 80 may include twosidewall images 81 a and 81 b that extend in the upward direction andthe depth direction. The sidewall image 81 a is positioned on the leftside in the horizontal direction, and the sidewall image 81 b ispositioned on the right side in the horizontal direction. A regionbetween the sidewall image 81 a and the sidewall image 81 b indicatesthe first predicted path 65 which the vehicle as the moving body 50 isexpected to follow. The space between the sidewall image 81 a and thesidewall image 81 b may be set to indicate the width of the moving body50. The sidewall images 81 a and 81 b are linear in FIG. 20. Thecontroller 33 may acquire the moving body information from thecommunication interface 31 and curve the sidewall images 81 a and 81 bon the basis of the predicted path. In this case, the moving bodyinformation includes a steering angle of the steering wheel.

The guide wall image 80 may include a plurality of distance wall images82 a, 82 b, and 82 c that extend in the height direction and thehorizontal direction and indicate the respective depth directiondistances from the moving body 50. The distance wall images 82 a, 82 b,and 82 c may connect the sidewall images 81 a and 81 b together. FIG. 20illustrates the three distance wall images 82 a, 82 b, and 82 c. Thenumber of distance wall images is not limited to three and may be two ormore than three. A depth-direction space between the distance wall image82 a and the distance wall image 82 b may be smaller than adepth-direction space between the distance wall image 82 b and thedistance wall image 82 c. The height-direction length of the distancewall images 82 a, 82 b, and 82 c may be either longer or shorter thanthe height-direction lengths of the sidewall images 81 a and 81 b.

A frame may be displayed on an outer periphery of each of the sidewallimages 81 a and 81 b and each of the distance wall images 82 a, 82 b,and 82 c of the guide wall image 80. The guide wall image 80 may includeat least one of an auxiliary line 84 a that extends in the depthdirection, an auxiliary line 84 b that extends in the horizontaldirection, and an auxiliary line 84 c that extends in the heightdirection. The guide wall image 80 may include all of the auxiliary line84 a that extends in the depth direction, the auxiliary line 84 b thatextends in the horizontal direction, and the auxiliary line 84 c thatextends in the height direction. The auxiliary line 84 a that extends inthe depth direction may be displayed on the sidewall images 81 a and 81b. The auxiliary line 84 b that extends in the horizontal direction maybe displayed on the distance wall images 82 a, 82 b, and 82 c. Theauxiliary line 84 c that extends in the height direction may bedisplayed on the sidewall images 81 a and 81 b and the distance wallimages 82 a, 82 b, and 82 c. Each of the auxiliary lines 84 a, 84 b, and84 c may be in any appropriate number. When a plurality of lines of eachof the auxiliary lines 84 a, 84 b, and 84 c are provided, each of theauxiliary lines 84 a, 84 b, and 84 c have equal spaces therebetween. Thespace between each of the plurality of auxiliary lines 84 a, 84 b, and84 c may be varied according to conditions such as a height from theroad surface, a distance from the moving body 50, and the like. Theframe displayed on the outer periphery of each of the sidewall images 81a and 81 b and the distance wall images 82 a, 82 b, and 82 c may beconsidered as a portion of each of the plurality of auxiliary lines 84a, 84 b, and 84 c. When a plurality of lines of each of the auxiliarylines 84 a, 84 b, and 84 c are provided, only one of them isappropriately denoted by the corresponding reference sign in FIG. 20 andother diagrams described below.

When the distance wall image 82 a is mapped in the real space capturedin the first video images, the distance wall image 82 a serves as afirst distance wall image that is located closer to the moving body 50than the wall images 82 b and 82 c. The distance wall image 82 a may bein different color from the colors of the distance wall images 82 b and82 c. For example, the distance wall images 82 b and 82 c may be intranslucent white, and the distance wall image 82 a may be intranslucent red. The sidewall images 81 a and 81 b may be in translucentwhite. The color described above are set by way of example, and thesidewall images 81 a and 81 b may be in color different from the colorsof the distance wall images 82 b and 82 c.

The transmittances of the sidewall images 81 a and 81 b may be varied inthe depth direction. The transmittances of the sidewall images 81 a and81 b may be set to increase from the front side to the rear side in thedepth direction. The color saturation and brightness of the sidewallimages 81 a and 81 b may be varied in the depth direction. For example,the color saturation may decrease from the front side in the depthdirection. The color saturation may also be referred to as colordensity. The sequential transition of the transmittance, colorsaturation, brightness, and chromaticity can be said to be gradation.

The transmittance of each of the distance wall images 82 a, 82 b, and 82c may be varied in accordance with the height from the road surface. Thetransmittance of each of the distance wall images 82 a, 82 b, and 82 cmay be set to increase as the height from the road surface in the heightdirection increases. The color saturation or the brightness of each ofthe distance wall images 82 a, 82 b, and 82 c may be varied inaccordance with the height from the road surface. For example, the colorsaturation may decrease as the height from the road surface increases.

The auxiliary lines 84 b and 84 c on the distance wall image 82 aserving as the first distance wall image may be in the same color as theauxiliary lines 84 b and 84 c of the distance wall images 82 b and 82 c.The auxiliary lines 84 a, 84 b, and 84 c may be in any color. Forexample, when the wall surfaces of the guide wall image 80 except forthe distance wall image 82 a are in white, the auxiliary lines 84 a, 84b, and 84 c may be in white having the brightness higher than the wallsurfaces or having the transmittance lower than the wall surfaces.

The controller 33 may detect the vehicle 64 displayed in the displayregion 62 of the first video images as the detection object. In theexample of FIG. 20, the vehicle 64 is located within the first predictedpath 65. The detection object detected by the controller 33 is notlimited to a vehicle and may include, for example, a building, a fence,an obstacle on the road, a person, an animal, and the like. When thecontroller 33 detects a detection object, the controller 33 cansynthesize the first recognition wall image 83 on a detection objectside of the moving body 50. When the controller 33 detects a detectionobject, the controller 33 may change the height-direction length of theguide wall image 80. When the controller 33 detects a detection object,the controller 33 may reduce the height-direction length of the guidewall image 80. In this way, the controller 33 can clarify the displaywhen the first recognition wall image 83 is displayed and draw attentionof the subject 60 to the detection object.

The first recognition wall image 83 of the detection object locatedwithin the first predicted path 65 extends in the height direction andthe horizontal direction. The first recognition wall image 83 may bedisplayed as an opaque or translucent surface in any color. In FIG. 20,the first recognition wall image 83 is displayed as a translucentrectangle surface positioned on the side of the vehicle 64 opposing tothe moving body 50. The horizontal direction width of the firstrecognition wall image 83 may match the width of the vehicle 64. Thehorizontal direction width of the first recognition wall image 83 maysubstantially match the width of the vehicle 64. The height of the firstrecognition wall image 83 may be set to a predetermined value. Thetransmittance of the first recognition wall image 83 may be varied inaccordance with the height from the road surface. The transmittance ofthe first recognition wall image 83 may be set to increase as the heightfrom the road surface increases. The color saturation or the brightnessof the first recognition wall image 83 may be varied in accordance withthe distance from the road surface in the height direction. For example,the color saturation may decrease as the distance from the road surfacein the height direction increases. The first recognition wall image 83may include auxiliary lines that extend in the horizontal direction andthe height direction.

The controller 33 may shift the auxiliary lines of the first recognitionwall image 83, which extend in the horizontal direction, in the heightdirection within the frame of the first recognition wall image 83. Theauxiliary lines may be displayed in such a manner as to appear from thebottom edge region of the frame of the first recognition wall image 83and vanish at the top edge region of the frame. The controller 33 maydisplay both of or any one of a relative position of the moving body 50and the vehicle 64 and a change of a relative distance therebetween byshifting, in the height direction, the auxiliary line of the firstrecognition wall image 83 that extends in the horizontal direction. Forexample, when the distance between the moving body 50 and the vehicle 64is decreasing, the controller 33 may shift, in the height direction, theauxiliary line that extends in the left-right direction at a high speed.The controller 33 may shift the auxiliary line in the height directionfaster as the distance between the moving body 50 and the vehicle 64 isshorter. The controller 33 may shift, in the height direction, theauxiliary line of the first recognition wall image 83 that extends inthe horizontal direction regardless of the location of, and the distancefrom, the detection object.

The color of the first recognition wall image 83 may be varied inaccordance with the depth direction distance between the moving body 50and the vehicle 64. For example, when the distance between the movingbody 50 and the vehicle 64 is longer than a predetermined distance asillustrated in FIG. 20, the controller 33 may display the firstrecognition wall image 83 in blue. When the moving body 50 movesrearward reducing the distance to the vehicle 64, the controller 33 maychange the color of the first recognition wall image 83 from blue toyellow and then to red.

When the distance between the moving body 50 and the vehicle 64 islonger than the predetermined distance, the controller 33 does not needto display the first recognition wall image 83. When the moving body 50and the vehicle 64 relatively approach each other and the distancetherebetween reaches the predetermined distance, the controller 33displays the first recognition wall image 83 after, for example,highlighting the vehicle 64 in the second video image. Such highlightingincludes displaying the outline of the vehicle 64 in bold lines,flashing the outline of the vehicle 64, painting the image of thevehicle 64, or the like. The controller 33 may change the display modein accordance with a change in the relative position with respect to thevehicle 64. For example, when the vehicle 64 relatively moves away fromthe moving body 50, the first recognition wall image 83 does not need tobe displayed.

FIG. 21 is a diagram illustrating an example of the second video imagein a state in which the distance between the moving body 50 and thevehicle 64 decreases when the moving body 50 moves rearward. The firstrecognition wall image 83 is displayed in red. Thus, the subject 60 canbe warned about the risk that further rearward movement may lead tocollision with the vehicle 64.

When the detection object and the guide wall image 80 overlap with eachother, the controller 33 may change the display of the guide wall image80. For example, the controller 33 may hide at least a portion of theguide wall image 80 that overlaps with the vehicle 64 in the secondvideo image as illustrated in FIG. 21. In particular, the controller 33does not display, in the display apparatus 40, the portion of the guidewall image 80 that overlaps with the vehicle 64 and positioned remotefrom the moving body 50 in the depth direction from the vehicle 64 orthe first recognition wall image 83. Thus, the display apparatus 40 candisplay a simple and intuitive image to the subject 60. The manner inwhich the display of the guide wall image 80 is changed is not limitedto hiding an overlapping portion. For example, the controller 33 mayincrease the transmittance of the portion of the guide wall image 80which overlaps with the detection object.

Example Variations

The guide wall image 80 is not limited to the examples illustrated inFIG. 20 and FIG. 21. FIG. 22 to FIG. 24 illustrate example variations ofthe guide wall image 80.

First Example Variation

In an example illustrated in FIG. 22, one of the auxiliary lines 84 b ofeach of the distance wall images 82 a, 82 b, and 82 c that extends inthe horizontal direction and is positioned lowest in the heightdirection may be displayed. The distance wall image 82 a that includesthe auxiliary line 84 b in the lowest position alone can enable easyrecognition of the height from the ground surface. The distance wallimage 82 a that includes the auxiliary line 84 b in the lowest positionalone can enable easy recognition of the distance from the recognitionwall image. At each end of the distance wall images 82 a, 82 b, and 82 cin the horizontal direction, an auxiliary line 84 c that extends in theheight direction may be displayed. On each of the outer peripheries ofthe distance wall images 82 a, 82 b, and 82 c, the auxiliary line 84 bpositioned at the bottom and the auxiliary lines 84 c that arepositioned at the horizontal ends and extends in the height direction atthe left-right direction ends may be displayed. Each of the distancewall images 82 a, 82 b, and 82 c may be displayed by the auxiliary line84 b that extends in the horizontal direction at the bottom of the outerperiphery and the auxiliary lines 84 c that extend in the heightdirection at the left-right direction ends.

Each of the distance wall images 82 a, 82 b, and 82 c may include asemi-transparent surface. Each of the distance wall images 82 a, 82 b,and 82 c may have the transmittance that increases, or a colorsaturation that decreases, moving away from the road surface in theheight direction. The auxiliary lines 84 b and 84 c positioned on theouter periphery of the distance wall image 82 a closest to the movingbody 50 may be displayed in color different from the other auxiliarylines. For example, the auxiliary lines 84 b and 84 c may be red. Theother auxiliary lines may be, but are not limited to, white. The firstrecognition wall image 83 displayed in front of the vehicle 64 may bedisplayed as a semitransparent surface in any color such that thetransmittance increases or the color saturation decreases moving awayfrom the road surface in the height direction. The top edge boundary ofthe first recognition wall image 83 may be hidden such that the firstrecognition wall image 83 is displayed to gradually vanish in the heightdirection.

In the example illustrated in FIG. 22, two auxiliary lines 84 aextending in the depth direction of the side wall images 81 a and 81 bof the guide wall image 80 at the top and bottom thereof are displayed.Auxiliary lines 84 a ₁ positioned at the bottom may be displayed tostandout more than auxiliary lines 84 a ₂ positioned at the top. To makethe line stand out, a bold line, a line with lower transmittance, abrighter line and the like may be used. The auxiliary lines 84 a ₂positioned at the top and the auxiliary lines 84 a ₁ positioned at thebottom may be displayed by the lines in the same display mode. The linesin the same display mode include lines having similar thicknesses,transmittances, brightnesses, and the like.

Each of the auxiliary line 84 a extending in the depth direction may bedisplayed so as to become gradually paler and vanish at the farthestposition in the depth direction. The side wall images 81 a and 81 b maybe displayed in such a manner that the edge regions thereof at thefarthest position in the depth direction are visible.

The auxiliary lines 84 c of the side wall images 81 a and 81 b extendingin the height direction may be displayed at least at the edge regions ofthe most front side and positions intersecting with the distance wallimages 82 a, 82 b, and 82 c. These auxiliary lines 84 c extending in theheight direction may be displayed to standout more than other auxiliarylines 84 c extending in the height direction. The auxiliary lines 84 cextending in the height direction may have different thicknesses. Amongthe auxiliary lines 84 c, the auxiliary lines 84 c displayed at theintersections with the distance wall image 82 a may be bolder than theauxiliary lines 84 c displayed at the intersections with the distancewall images 82 b and 82 c.

Second Example Variation

The guide wall image 80 illustrated in FIG. 23 is different from theguide wall image 80 of FIG. 22 with respect to the side wall images 81 aand 81 b. In FIG. 23, at least two auxiliary lines 84 a positioned atthe top and bottom extending in the depth directions of the side wallimages 81 a and 81 b of the guide wall image 80 may be displayed. Amongthe auxiliary lines 84 a extending in the depth direction, the onepositioned lowermost in the height direction may be displayed tostandout more than the others. A plurality of auxiliary lines 84 a maybe displayed by the lines in the same display mode. The guide wall image80 of FIG. 23 may employ the variations in transmittance, color, andcolor arrangement that may be employed by the guide wall image 80 ofFIG. 22.

Third Example Variation

The guide wall image 80 illustrated in FIG. 24 is different from theguide wall image 80 of FIG. 22 with respect to the side wall images 81 aand 81 b. In FIG. 24, the auxiliary lines 84 a of the side wall images81 a and 81 b of the guide wall image 80 that extend in the depthdirection and positioned on the bottom are displayed. The auxiliarylines 84 a of the guide wall image 80 that extend in the depth directionand positioned on the bottom may correspond to lines on the road surfacemapped to the real space captured in the first video images togetherwith the auxiliary lines 84 b extending in the horizontal direction. Theguide wall image 80 of FIG. 24 may employ the variations intransmittance, color, and color arrangement that may be employed by theguide wall image 80 of FIG. 22. The auxiliary lines 84 c extending inthe height direction may have different thicknesses. The thicknesses ofthe auxiliary lines 84 c arranged from the front side in the depthdirection may decrease in the depth direction.

In the guide wall image 80 illustrated in each of FIG. 20 to FIG. 24,the display apparatus 40 may omit some or all of the auxiliary lines 84a, 84 b, and 84 c.

Seventh Example

FIG. 25 illustrates a seventh example of the detection region 61 of thefirst video image obtained by the image processing apparatus 30 from theimaging apparatus 20. In the example illustrated in FIG. 25, thedetection region 61 is longer in the left-right direction than theup-down direction. The display region 62 is positioned at the center ofthe left-right direction of the detection region 61. The display region62 is not limited to a portion of the detection region 61 and may coverthe detection region 61 in its entirety.

In the seventh example, the moving body 50 is a vehicle moving rearwardtoward a parking space in a parking lot. The imaging apparatus 20 may bepositioned on the rear side of the moving body 50 and capture a reararea behind the moving body 50. The controller 33 may detect, from thedetection region 61, each of the vehicle 64 b and the pedestrian 63displayed at least partially in the display region 62 outside of thefirst predicted path 65 and inside of the display region 62 as detectionobjects. In the example illustrated in FIG. 25, the controller 33determines that the vehicle 64 a in the first predicted path 65 of themoving body 50 is located farther than a predetermined depth directiondistance and thus does not treat the vehicle 64 a as the detectionobject.

FIG. 26 illustrates an example of the second video image correspondingto the display region 62 of the first video image illustrated in FIG.25. The controller 33 recognizes the vehicle 64 b and the pedestrian 63as the detection objects located inside of the display region 62 of thefirst video image and displays the first recognition wall images 83 aand 83 b configured as virtual flat planes on the portions of thevehicle 64 b and the pedestrian 63 opposing to the moving body 50. Eachof the first recognition wall images 83 a and 83 b may be displayed as atranslucent planes parallel to the side wall images 81 a and 81 bextending in the height direction and the depth direction. Thecontroller 33 may acquire changes in the distances between the relativepositions of the vehicle 64 b and the moving body 50 and between therelative positions of the pedestrian 63 and the moving body 50 anddisplay the side wall images 81 a and 81 b when the relative positionschange in a direction reducing the distance. In a manner similar to theabove, any appropriate algorithm may be employed for the estimation ofthe distance between the moving body 50 and the detection objects.

The controller 33 may estimate the horizontal direction distancesbetween the vehicle 64 a and the pedestrian 63 as the detection objectsand the guide wall image 80 and determine the colors of the firstrecognition wall images 83 a and 83 b on the basis of the estimateddistances. Here, the distances between the detection objects and theguide wall image 80 refers to distances between the detection objectsand a virtual guide wall displaying the guide wall image 80 that isassumed to be present in the real space in the first video image. Thecontroller 33 may estimate the first distance between positions of thedetection objects and the position of the guide wall image 80 on thebasis of a position in which the guide wall image 80 is mapped in thereal space captured in the first video image and the positions of thedetection objects. The controller 33 may provide a threshold of thefirst distance and cause the display apparatus 40 to display each of thefirst recognition wall images 83 a and 83 b in different colors such asblue, yellow, red, or the like in the stated order from one with alonger horizontal direction distance. Each of the first recognition wallimages 83 a and 83 b may include an auxiliary line that extends in thedepth direction. The controller 33 may shift the auxiliary lines of thefirst recognition wall images 83 a and 83 b, which extend in the depthdirection, in the height direction within the frame of the firstrecognition wall image 83 in a manner similar to the auxiliary lines ofthe first recognition wall image 83 of FIG. 20 that extend in thehorizontal direction.

The controller 33 estimates first positions as the depth directionlocations of the vehicle 64 b and the pedestrian 63 as the detectionobjects. The controller 33 may at least partially change the display ofthe side wall images 81 a and 81 b opposing the vehicle 64 b and thepedestrian 63 in correspondence with the first positions. The change inthe display mode includes a change of color of the wall surface,brightness, color saturation, color or thickness of the frame and/orauxiliary line, or any combination thereof. For example, colors of aportion 81 a ₁ of the side wall image 81 a opposing the vehicle 64 b anda portion 81 b ₁ of the side wall image 81 b opposing the pedestrian 63are changed in FIG. 26. The portions of the side wall images 81 a and 81b may correspond to regions defined by the auxiliary lines 84 c of theside wall images 81 a and 81 b that extend in the height direction. Thecolors of the portions 81 a ₁ and 81 b ₁ of the side wall images 81 aand 81 b may be varied on the basis of the first distance. When thedetection object is a large obstacle relative to the length indicated bythe side wall images 81 a and 81 b, the controller 33 may change thecolors of the side wall image 81 a or the side wall image 81 b in itsentirety. Such a large obstacle may include a large vehicle such as atrailer, building, or the like.

When the detection object moves, the controller 33 may estimate thesecond predicted path of the detection object and estimate the firstposition as a position at which the second predicted path and the sidewall images 81 a and 81 b intersect with one another. The controller 33may estimate the first position as a position at which the secondpredicted path in the real space captured in the first video images andthe side wall images 81 a and 81 b mapped to the real space intersectwith one another. The controller 33 may change the display of the sidewall images 81 a and 81 b at least partially on the basis of the firstposition. In this case also, the colors of the portions 81 a ₁ and 81 b₁ of the side wall images 81 a and 81 b may be changed on the basis ofthe first distance. When the detection object is a very large obstacle,the controller 33 may change the colors of the side wall image 81 a orthe side wall image 81 b in their entirety.

In another display mode, the controller 33 may change the display ofportions of the side wall images 81 a and 81 b positioned farther in thedepth direction from the first recognition wall images 83 a and 83 b. Inyet another display mode, the controller 33 may change the display ofportions of the side wall images 81 a and 81 b positioned farther in thedepth direction from positions where the second predicted paths and theside wall images 81 a and 81 b intersect with one another.

The display of the first recognition wall images 83 a and 83 b may bechanged on the basis of their heights from the road surface. Thetransmittance, color saturation, brightness and the like of the firstrecognition wall images 83 a and 83 b may be varied on the basis of theheights thereof from the road surface, in a manner similar to the firstrecognition wall image 83 of the sixth example.

As described above, the display system 10 can spatially display thedistance to and/or location of a detection object that can be anobstruction to the rearward movement in a three-dimensional manner byusing the guide wall image 80 and the first recognition wall images 83 aand 83 b. Also, from the predicated path of the detection object inmotion, a position where there is a risk of collision may be displayedin a three-dimensional manner. As described above, the display system 10can spatially display a detection object and warning content in athree-dimensional manner by displaying each of the guide wall image 80and the first recognition wall images 83 a and 83 b as a wall (or aplane) having a height. Thus, the subject 60 can easily recognize thedisplay and the warning content.

Eighth Example

FIG. 27 illustrates an eighth example of the detection region 61 of thefirst video image acquired from the imaging apparatus 20 by the imageprocessing apparatus 30. The imaging apparatus 20 may be arranged tocapture a rear area behind the moving body 50 as the vehicle. In theexample illustrated in FIG. 27, the detection region 61 is longer in theleft-right direction than the up-down direction. The display region 62is positioned at the center of the left-right direction of the detectionregion 61. The controller 33 may detect each of the pedestrian 63 andthe vehicle 64 b as the detection objects captured in the second regioninside of the detection region 61 and outside of the display region 62of the first video image. In the eighth example, the controller 33determines that a depth direction distance to the vehicle 64 a capturedin the display region 62 is longer than a predetermined distance andthus does not treat the vehicle 64 a as a detection object.

FIG. 28 is a diagram schematically illustrating locations of the movingbody 50 and the pedestrian 63 and the vehicle 64 b as the detectionobjects viewed from above along the height direction in the real spacecaptured in the first video image. The imaging apparatus 20 can capturesubjects within regions F₁ and F₂ in the real space. The regions F₁ andF₂ correspond to the detection region 61 of the first video image. Theregion F₁ is the first region corresponding to the display region 62 ofthe first video image. The region F₂ corresponds to the second regioninside of the detection region 61 of the first video image and outsideof the display region 62.

FIG. 28 illustrates a virtual guide wall 90 in broken lines obtained bymapping the guide wall image 80 of the second video image in the realspace, for the purpose of illustration. Virtual side walls 91 a and 91 bcorrespond to the side wall images 81 a and 81 b displayed in the secondvideo image, respectively. Virtual distance walls 92 a, 92 b, and 92 ccorrespond to the distance wall images 82 a, 82 b, and 82 c in thesecond video image, respectively.

In FIG. 28, also, each of virtual lines 95 l ₁ to 95 l ₅ and 95 r ₁ to95 r ₅ shown as broken lines indicates a horizontal direction distancebetween the virtual side walls 91 a and 91 b of the moving body 50 andthe detection object, for the purpose of illustration. The horizontaldirection distance is also referred to as a second distance. The virtuallines 95 l ₁ to 95 l ₅ are positioned on the left side of the movingbody 50. The virtual lines 95 r ₁ to 95 r ₅ are positioned on the rightside of the moving body 50. Intervals between the virtual lines 95 l ₁to 95 l ₅ and between the virtual lines 95 r ₁ to 95 r ₅ may beappropriately determined. Intervals between the virtual lines 95 l ₁ to95 l ₅ and between the virtual lines 95 r ₁ to 95 r ₅ may be equal toone another. The controller 33 can determine which one of the virtuallines 95 r ₁ to 95 r ₅ and 95 r ₁ to 95 r ₅ is closest to the detectionobject, or which two of the virtual lines 95 l ₁ to 95 l ₅ and 95 r ₁ to95 r ₅ include the detection object in a region therebetween, on thebasis of the first video image.

The second video image corresponding to the first video image of FIG. 27is illustrated in FIG. 29 by way of example. In the eighth example, theguide wall image 80 may be displayed in a display method similar tothose described in the sixth example and the seventh example. When thedetection objects are located in the second region of the first videoimage, the controller 33 synthesizes the second recognition wall images89 a and 89 b in the edge region on the side where the detection objectsare located in the second video image. The second recognition wallimages 89 a and 89 b may include wall portions 96 a and 96 b extendingin the height direction and the depth direction and floor portions 97 aand 97 b extending in the depth direction and the horizontal direction.The wall portions 96 a and 96 b extend from the bottom edge region totop edge region in the left-side and right-side edge regions of thesecond video image in FIG. 29. The wall portions 96 a and 96 b mayextend partially in the up-down direction at the left-side andright-side edge regions of the second video image instead of extendingthroughout the up-down direction. Similarly, the floor portions 97 a and97 b may extend partially or entirely in the left-right direction at thebottom edge of the second image. The floor portions 97 a and 97 b may bedisplayed between the guide wall image 80 and the bottom edge of thesecond video image.

The controller 33 may change the displays of the second recognition wallimages 89 a and 89 b on the basis of the second distances of thedetection objects. The change of display includes change of color,transmittance, color saturation, brightness, size, as well as dynamicdisplay methods including flashing and moving. In one of a plurality ofembodiments, the change of display may be, for example, a change ofcolor. As for the display color, red, yellow, and blue may correspond toa high risk, a medium risk, and a low risk, respectively. The pedestrian63 illustrated in FIG. 28 is located on the virtual line 95 r ₃ which isthe third to the right side in the horizontal direction from the virtualside wall 91 b of the moving body 50. In this case, the controller 33may determine that there is a medium risk and display the secondrecognition wall image 89 b on the right side in yellow. Also, thevehicle 64 b illustrated in FIG. 28 is located remote from the virtualline 95 l ₅ which is fifth to the left side in the horizontal directionfrom the virtual side wall 91 a of the moving body 50. In this case, thecontroller 33 may determine that there is a low risk and display thesecond recognition wall image 89 a on the left side in blue. In one ofthe plurality of embodiments, the change of the displays may include alateral movement of the auxiliary lines 96 a ₁ and 96 b ₁ thatvertically extend in the wall portions 96 a and 96 b. The controller 33may change the moving speed of the wall portions 96 a and 96 b inaccordance with the length of the second distance.

The second recognition wall images 89 a and 89 b may be semitransparent.Display characteristics of each of the wall portion 96 a of the secondrecognition wall image 89 a and the wall portion 96 b of the secondrecognition wall image 89 b may be varied in the up-down direction. Forexample, each of the wall portion 96 a of the second recognition wallimage 89 a and the wall portion 96 b of the second recognition wallimage 89 b may have a transmittance that decreases in the downwarddirection. Also, each of the second recognition wall image 89 a and thesecond recognition wall image 89 b may have a color density thatincreases in the upward direction. Display characteristics of each ofthe floor portion 97 a of the second recognition wall images 89 a andthe floor portion 97 b of the second recognition wall images 89 b may bevaried in the left-right direction. For example, the floor portion 97 aof the second recognition wall image 89 a may have a transmittance thatincreases from the left side toward the center of the second videoimage, and the floor portion 97 b of the second recognition wall image89 b may have a transmittance that increases from the right side towardthe center of the second video image. Also, the floor portion 97 a ofthe second recognition wall image 89 a may have a color saturation thatdecreases from the left side toward the center of the second image, andthe floor portion 97 b of the second recognition wall image 89 b mayhave a color saturation that decreases from the right side toward thecenter of the second image. The color saturation can also be referred toas a color density of the image.

The controller 33 may determine the types of the detection objects anddisplay icon images 99 a and 99 b corresponding to the types on thefloor portions 97 a and 97 b of the second recognition wall images 89 aand 89 b. A known technology may be employed for the determination ofthe type on the basis of the image of the detection object detected inthe first video images. For example, the controller 33 may determine thetype of an object by performing pattern matching of an outline shape ofthe detection object using a model pattern. For example, an icon of aperson motif may be selected for the pedestrian 63, and an icon of avehicle motif may be selected for the vehicle 64 b. The controller 33can estimate the second distance in the horizontal direction between thevirtual side walls 91 a and 91 b obtained by mapping the side wallimages 81 a and 81 b in the real space and the detection object in thereal space. The second distance can be determined on the basis of apositional relationship between each line obtained by mapping thevirtual lines 95 l ₁ to 95 l ₅ and 95 r ₁ to 95 r ₅ in the real spaceonto the detection region 61 of the first video image and the image ofeach of the detection objects. The controller 33 may change the displaypositions of the icon images 99 a and 99 b on the basis of the seconddistance.

In the display example of the second video image illustrated in FIG. 29,first distance recognition lines 98 l ₁ to 98 l ₅ and 98 r ₁ to 98 r ₅are provided in a manner corresponding to the virtual lines 95 l ₁ to 95l ₅ and 95 r ₁ to 95 r ₅ of the real space, respectively. The firstdistance recognition lines 98 l ₁ to 98 l ₅ are positioned on the leftside of the side wall image 81 a and arranged sequentially from thecenter to the left side. The first distance recognition lines 98 r ₁ to98 r ₅ are positioned on the right side of the side wall image 81 b andarranged sequentially from the center to the right side. Each of thefirst distance recognition lines 98 l ₁ to 98 l ₅ and 98 r ₁ to 98 r ₅indicates a display position of the icon images 99 a and 99 b and doesnot need to be displayed in the second video image.

In FIG. 28, the pedestrian 63 is located on the virtual line 95 r ₃,which is the third on the right side in the horizontal direction fromthe virtual side wall 91 b of the moving body 50. Thus, the controller33 may display the icon image 99 b of the pedestrian 63 on the firstdistance recognition line 98 r 3, which is the third on the right side,in the second video image of FIG. 29. As illustrated in FIG. 29, theicon image 99 b may be displayed in the three-dimensional manner as asurface having a depth-direction length and a height-direction length onthe first distance recognition line 98 r ₃ extending in the depthdirection in the second video image. When viewed stereoscopically, theicon image 99 b may be displayed as a surface parallel to the sidewallimages 81 a and 81 b and the second recognition wall images 89 a and 89b. The display mode of the icon image 99 b such as the color, colorsaturation, and brightness may be changed on the basis of the seconddistance, in a manner similar to the second recognition wall 89 b. Forexample, the icon image 99 b may be displayed in yellow.

In FIG. 28, the vehicle 64 b is located remote from the virtual line 95l ₅ which is the fifth on the left side in the horizontal direction fromthe virtual side wall 91 a of the moving body 50. In this case, thecontroller 33 may position the icon image 99 a of the vehicle 64 b onthe first distance recognition line 98 l ₅ positioned on the left sidein the second video image of FIG. 29. Alternatively, the controller 33may arrange the icon image 99 a such that the icon image 99 a seems tobe positioned on the same surface as the wall portion 96 a of the secondrecognition wall image 89 a when the second video image is viewedstereoscopically. The display mode of the icon image 99 a may be changedon the basis of the second distance, in a manner similar to the iconimage 99 b. For example, the icon image 99 a may be displayed in blue.

When one or both of the moving body 50 and the detection objects moveand the position of the detection object relative to the moving body 50changes, the position and the display mode of each of the secondrecognition wall images 89 a and 89 b and each of the icon images 99 aand 99 b also change. When the moving body 50 enters the display region62, the detection objects may be displayed in the display mode asdescribed in the seventh example. An example of a change in the displaymode when the vehicle 64 b moves from the region F₂ to the region F₁ inthe real space illustrated in FIG. 28 will be described.

First, it is assumed that the vehicle 64 b is located on the left sideof the virtual line 95 l ₅ in the real space in FIG. 28. At this time,as described above, the second recognition wall image 89 a is displayedin the second video image of FIG. 29 and, simultaneously, the icon image99 a is displayed on the leftmost side of the floor portion 98 a of thesecond recognition wall image 89 a. At this time, the second recognitionwall image 89 a and the icon image 99 a may be displayed in blue.

In the real space of FIG. 28, as the vehicle 64 b approaches closer tothe virtual guide wall 90, the display mode of the second recognitionwall image 89 a displayed in the second video image of FIG. 29 ischanged. For example, the color of the second recognition wall image 89a is sequentially changed from blue to yellow and then to red.Concurrently, the display position of the icon image 99 a is moved fromthe first distance recognition line 98 l ₅ to the first distancerecognition line 98 l ₁. The color of the icon image 99 a may besequentially changed from blue to yellow and then red. Thus, the subject60 can recognize that the vehicle 64 b is approaching outside of thesecond video image. Also, because the three-dimensional display isemployed, the subject 60 can spatially recognize the approach of thevehicle 64 b, and the probability of oversight of information can bereduced.

When the vehicle 64 b is approaching the moving body 50, the icon image99 a may be moved toward the center of the image. The subject 60 canrecognize the moving direction of the vehicle 64 b by viewing themovement of the icon image 99 a.

Further, when the vehicle 64 b enters the region F₁ from the region F₂in the real space of FIG. 28, the vehicle 64 b enters the display regionof the first video images and thus is included in the second videoimages and displayed on the display apparatus 40. Also, the secondrecognition wall image 89 a is hidden, and the first recognition wallimage 83 a is displayed on the side of the vehicle 64 b opposing theguide wall image 80 as illustrated in FIG. 26. When the secondrecognition wall image 89 a is hidden, the controller 33 may flash thesecond recognition wall image 89 a a plurality of times so as to alertthe subject 60. The controller 33 displays the first recognition wallimage 83 a on the side of the vehicle 64 b opposing to the moving body50. Further, the controller 33 estimates the second predicted path ofthe vehicle 64 b and estimates the first position where the secondpredicted path and the side wall images 81 a and 81 b intersect with oneanother. The controller 33 may change the display mode of the portion 81a ₁ of the side wall image 81 a that includes the first position. Thecontroller 33 may sequentially change the color of the portion 81 a ₁ ofthe side wall image 81 a from, for example, blue to yellow and then tored, as the vehicle 64 b approaches closer. This enables the subject 60to easily recognize that the vehicle 64 b is approaching and also thatthe second predicted path of the vehicle 64 b overlaps with the firstpredicted path 65 of the moving body 50.

According to the one of the plurality of embodiments of the presentdisclosure, as described above, the three-dimensional displays of theguide wall image, the first recognition wall image, and the secondrecognition wall image facilitate the spatial recognition of a positionof a detection object. According to the one of the plurality ofembodiments of the present disclosure, also, the change of the displaymode of each of the wall surfaces facilitates recognition of informationsuch as a caution and warning. Further, the three-dimensional displaycan reduce the probability of oversight of the information.

Example Variation

FIG. 30 illustrates another example of the second video imagecorresponding to the first video image of FIG. 27. View display regions101 and 102 that indicate a selection state between “Normal ViewDisplay” and “Wide View Display” are added to the lower left portion inFIG. 30. The “Normal View Display” and the “Wide View Display” will bedescribed later. Some of the display modes of the guide wall image 80,the second recognition wall images 89 a and 89 b, and the icon images 99a and 99 b in FIG. 30 may be different from those of FIG. 29. Forexample, FIG. 30 illustrates the guide wall image 80 in the display modesimilar to that of FIG. 22.

The wall portions 96 a and 96 b of the second recognition wall images 89a and 89 b may include at least auxiliary lines 96 a ₁ and 96 b ₁,respectively, that extend in the height direction. One of the pluralityof auxiliary lines 96 a ₁ of the wall portion 96 a and one of theplurality of auxiliary lines 96 b ₁ of the wall portion 96 b are denotedwith the respective reference signs in FIG. 30. The wall portions 96 aand 96 b of the second recognition wall images 89 a and 89 b mayindicate the distance to the detection object by using a color and mayhave transmittance that varies from the front side to the rear side inthe depth direction. The wall portions 96 a and 96 b may havetransmittances that gradually increase in the height direction or mayhave color saturations that gradually decrease and vanish at apredetermined height position.

By changing the transmittance and the color saturation of the wallportions 96 a and 96 b and the display modes of the auxiliary lines 96 a₁ and 96 a ₂, the controller 33 can indicate that an object is presentwithin the predetermined distance range and also indicate a distance tothe detection object or a change of the distance to the detectionobject. The change of the transmittance or the color saturation of thewall portions 96 a and 96 b may be referred to as change in gradation.For example, the controller 33 may indicate that a detection object ispresent within the predetermined distance by moving the auxiliary lines96 a ₁ and 96 a ₂ of the wall portions 96 a and 96 b. The controller 33may indicate that a detection object is present within the predetermineddistance by increasing the color saturations of the front portions ofthe wall portions 96 a and 96 b to a maximum and gradually reducingtheir color saturations in the depth direction. The auxiliary lines 96 a₁ and 96 b ₁ of the wall portions 96 a and 96 b and the changes in theirtransmittances are not essential. The controller 33 may omit theauxiliary lines 96 a ₁ and 96 b ₁ from the wall portions 96 a and 96 b.The controller 33 does not need to display changes (the gradations) inthe transmittances of the wall portions 96 a and 96 b.

The floor portions 97 a and 97 b of the second recognition wall images89 a and 89 b are provided with one or more second distance recognitionlines 100 l and 100 r, respectively, in addition to the first distancerecognition lines 98 l and 98 r. In FIG. 30, a plurality of the seconddistance recognition lines 100 l, 100 r exist but for each only onereference sign is denoted. The first distance recognition lines 98 l and98 r and the second distance recognition lines 100 l and 100 r do notneed to be displayed on the display. The first distance recognitionlines 98 l and 98 r may correspond to the horizontal direction distancesbetween the moving body 50 and the detection objects, and the seconddistance recognition lines 100 l and 100 r may correspond to the depthdirection distances between the moving body 50 and the detectionobjects. Each of the plurality of the second distance recognition walls100 l and 100 r may correspond to the depth direction distance when theauxiliary lines 84 c of the side wall images 81 a and 81 b extending inthe height direction are mapped in the real space.

The subject 60 can recognize the horizontal direction distance and thedepth direction distance to the detection object on the basis of thepositions of the icon images 99 a and 99 b on the floor portions 97 aand 97 b with respect to the horizontal direction and the depthdirection. The icon images 99 a and 99 b are three-dimensional imagescorresponding to the types of the detection objects. The floor portions97 a and 97 b may be positioned on the front side of the front ends ofthe side wall images 81 a and 81 b and within the lines extended fromthe side wall images 81 a and 81 b. The positional relationship betweenthe second recognition wall images 89 a and 89 b and the guide wallimage 80 is not limited thereto and may be changed appropriately.

In FIG. 30, the display apparatus 40 displays the view display regions101 and 102 that indicate the selection status between the “Normal ViewDisplay” and the “Wide View Display” in the lower right portion. The“Normal View Display” and the “Wide View Display” displays a video imagein different angles. In one of a plurality of embodiments, the “NormalView Display” corresponds to the angle of the display region 62 of thesecond video image illustrated in FIG. 4. In one of a plurality ofembodiments, the “Wide View Display” corresponds to the angle of thedetection region 61 of the first video image illustrated in FIG. 4. The“Wide View Display” does not need to display the detection region 61 ofthe first video image in its entirety and may display a video image inan angle that includes the “second video image” extracted from thedetection region 61. The second video images illustrated in and beforeFIG. 30 are displayed in the “Normal View Display”. Which one of the“Normal View Display” and the “Wide View Display” is selected for thevideo image being displayed is indicated by changing the display of theview display regions 101 and 102 indicating the selection status. Forexample, the change of the display of the view display regionsindicating the selection status includes a change of the color, thecolor saturation, and the color of characters of the view displayregions 101 and 102.

The controller 33 may change between the “Normal View Display” and the“Wide View Display” according to an image processing result of the firstvideo image, or upon receiving an input in respect of the displayapparatus 40 from the subject 60 and the like. For example, when thecontroller 33 detects the approach of a detection object in the “NormalView Display”, the controller 33 may change the displayed video image tothe “Wide View Display”. When the controller 33 does not detect adetection object within the predetermined region in the “Wide ViewDisplay”, the controller 33 may change the displayed video image to the“Normal View Display”. When the display apparatus 40 includes a touchpanel screen, the controller 33 may change the display mode uponreceiving a signal from the display apparatus 40 indicating that thesubject 60 has performed a selection by touching the view display region101 or 102 on the touch panel screen.

FIG. 31 is a diagram illustrating an example of a video image that hasbeen changed from the “Normal View Display” illustrated in FIG. 30 tothe “Wide View Display”. The view angle of the video image in the “WideView Display” is wider in the horizontal direction than that in the“Normal View Display” in FIG. 30. In FIG. 31, the pedestrian 63 and thevehicle 64 b located outside of the display region in the “Normal ViewDisplay” illustrated in FIG. 30 are displayed. In the video imageillustrated in FIG. 31, because the view angle is wider in thehorizontal direction than that in the “Normal View Display” of FIG. 30,the space between the side wall images 81 a and 81 b on the left rightsides of the guide wall image 80 is relatively reduced.

In FIG. 31, because the pedestrian 63 and the vehicle 64 b are withinthe display region, the second recognition wall images 89 a and 89 b arenot displayed. The controller 33 may recognize the vehicle 64 b and thepedestrian 63 as the detection objects within the detection region 61 ofthe first video image and display the first recognition wall images 83 aand 83 b as virtual flat planes on the sides of the vehicle 64 b and thepedestrian 63 opposing to the moving body 50. The controller 33estimates the locations of the vehicle 64 b and the pedestrian 63 as thedetection objects in the depth direction. On the basis of the estimatedlocations, the controller 33 may change the display of the side wallimages 81 a and 81 b opposing to the vehicle 64 b and the pedestrian 63.In FIG. 31, the display of the portion 81 b ₁ of the side wall image 81b and the portion 81 a ₁ of the side wall image 81 a are changed incorrespondence with the pedestrian 63 and the vehicle 64 b,respectively. Changes of display includes a variety of aspects. Forexample, the change of display includes changes of color, changes ofthickness of the auxiliary lines surrounding the outer periphery,changes of type of the lines, starting and stopping flashing, change toa flashing cycle, or the like. The display methods and the display modesof the first recognition wall images 83 a and 83 b, the portion 81 a 1of the side wall image 81 a, and the portion 81 b 1 of the side wallimage 81 b may be similar to those of the example of FIG. 26.

According to the one of the plurality of embodiments as illustrated inFIG. 30 and FIG. 31, the video image captured by the imaging apparatus20 may be displayed on the display apparatus 40 in the “Normal ViewDisplay” or the “Wide View Display” having different view angles in aswitchable manner. The “Normal View Display” enables the subject 60 toeasily recognize the presence and the location of the detection objectlocated outside of the region of the video image being displayed byviewing the second recognition wall images 89 a and 89 b and the iconimages 99 a and 99 b. The autonomous or manual switchover between the“Normal View Display” and the “Wide View Display” by the displayapparatus 40 enables the subject 60 to recognize the detection object,detected outside of the image in the “Normal View Display”, in the videoimage. The “Wide View Display” enables stereoscopic recognition of thepositional relationship with the detection object by displaying theguide wall image 80 and the first recognition wall image 83 b. In thisway, the display system 10 according to the one of the plurality ofembodiments can enable the subject 60 to easily grasp the surroundingsituation and be aware of risks.

Another Example

FIG. 32 illustrates another example of the second video image. FIG. 32corresponds to FIG. 24. In FIG. 32, the guide wall image 80 is displayedby white lines. In FIG. 32, the first recognition wall image 83 isdisplayed by white lines. In the example of FIG. 32, the second videoimage includes a first semitransparent image 80 a. In the example ofFIG. 32, the second video image includes a second semitransparent image83 c.

The controller 33 may generate the second video image by sequentiallysuperimposing a first image and a second image on the display region ofthe first video images obtained from the imaging apparatus 20. Thecontroller 33 may generate a synthesized image by sequentiallysuperimposing the first image and the second image in the stated orderon each frame image of the first video images. The controller 33 mayoutput the second video images and cause the display apparatus 40 todisplay the second video images. The second images may include the guidewall image 80 that indicates the first predicted path 65 of the movingbody 50. The first images include the first semitransparent image 80 a(a transmittance gradation image) that has a transmittance thatgradually increases moving in the upward direction. The controller 33may superimpose the guide wall image 80 on the first semitransparentimage 80 a. The controller 33 may superimpose the first semitransparentimage 80 a on the display region of the first video images. Thecontroller 33 may synthesize the first semitransparent image 80 abetween the display region of the first video images and the guide wallimage 80. The first semitransparent image 80 a has a transmittance thatgradually that decreases moving in the downward direction. The firstsemitransparent image 80 a changes its color to transparent toward thetop edge region from the bottom edge region. The first semitransparentimage 80 a gradually changes its color to transparent from a secondcolor different from a first color of the guide wall image 80. The firstcolor may include, for example, white or cyan. The second color mayinclude, for example, black.

By virtue of the color difference between the first color and the secondcolor, the guide wall image 80 can be easily viewed. By virtue of thecolor difference between the first color and the second color, the guidewall image 80 can be easily viewed in a situation where the first videoimage includes a large amount of color that is similar to the firstcolor. For the guide wall image 80 illustrated in the example of FIG.32, the first semitransparent image 80 a facilitates recognition on aground surface covered with snow. Because the guide wall image 80 hastransmittance that increases in the upward direction, the second imagebecomes similar to the first image in an upper portion of the guide wallimage 80. The second video image does not include a large amount ofadded color in regions displaying remote areas. The second video imageshave less impact on the visibility of the regions on the rear side ofthe guide wall image 80. Because the first semitransparent image 80 ahas transmittance that increases from the lower side to the upper side,it becomes easier to ascertain a sense of depth in the second videoimages. Because the first semitransparent image 80 a has transmittancethat increases from the lower side to the upper side, the second videoimage conveys a bright impression.

The controller 33 may generate the second video images by sequentiallysuperimposing the third image and the fourth image on the display regionof the detection object recognized in the first video image. The fourthimage may include the first recognition wall image 83 that indicates thepresence of the recognized detection object. The third image includesthe second semitransparent image 83 c. The controller 33 may superimposethe first recognition wall image 83 on the second semitransparent image83 c. The controller 33 may superimpose the second semitransparent image83 c on the display region of the detection object. The controller 33may synthesize the second semitransparent image 83 c between the displayregion of the detection object and the first recognition wall image 83.The second semitransparent image 83 c has a transmittance that graduallydecreases in the downward direction. The second semitransparent image 83c changes its color to transparent toward its top edge region from itsbottom edge region. The second semitransparent image 83 c graduallychanges its color to transparent from a fourth color different from athird color of the first recognition wall image 83. The secondsemitransparent image 83 c gradually changes from the fourth colordifferent from the third color of the first recognition wall image 83 toa transparent color. The third color may include, for example, red,yellow, and white or cyan. The second color may include, for example,black.

By virtue of the color difference between the third color and the fourthcolor, the first recognition wall image 83 can be easily recognized and,also, the first recognition wall image 83 may be easily recognized whena detection object is of color similar to the third color.

The presence of the second semitransparent image 83 c facilitatesrecognition of the first recognition wall image 83 in white asillustrated in the example of FIG. 32 when the first recognition wallimage 83 is displayed in front of a white track.

Although the present disclosure has been described based on variousfigures and embodiments, it should be appreciated that those who areskilled in the art may easily perform various changes or modificationson the basis of the present disclosure. Accordingly, such changes andmodifications are included in the scope of the present disclosure. Forexample, a function included in each means or each step may berearranged, avoiding a logical inconsistency, such that a plurality ofmeans or steps are combined, or a means or a step is subdivided.

For example, each constituent element and function of the display system10 in the above embodiment may be rearranged. For example, some or allof the configurations and functions of the image processing apparatus 30may be included in at least one of the imaging apparatus 20 and thedisplay apparatus 40.

Some of the constituent elements of the display system 10 in the aboveembodiment may be positioned outside of the moving body 5. For example,the image processing apparatus 30 and the like may be configured as acommunication apparatus such as a mobile phone or an external server andconnected to other constituent elements of the display system 10 in awired or wireless manner.

REFERENCE SIGNS LIST

-   -   10 display system    -   20 imaging apparatus    -   21 imaging optical system    -   22 image sensor    -   23 communication interface    -   24 controller    -   30 image processing apparatus    -   31 communication interface    -   32 memory    -   33 controller    -   40 display apparatus    -   50 moving body    -   51 network    -   60 subject    -   61 detection region    -   62 display region    -   63, 63 a, 63 b, 63 c, 63 d pedestrian    -   64, 64 a, 64 b vehicle    -   65 first predicted path    -   66 guide line    -   67 icon image    -   68 third marker    -   69 outline    -   70 region    -   71 first marker    -   72 second marker    -   73 fifth marker    -   73 a icon image    -   73 b band image    -   73 c right-side edge region    -   74 obstacle image    -   75 a, 75 b, 75 c sixth marker    -   80 first semitransparent image    -   81 a, 81 b side wall image    -   81 a ₁, 81 b ₁ portion of side wall image    -   82 a, 83 b, 82 c distance wall image    -   83, 83 a, 83 b first recognition wall image    -   83 c second semitransparent image    -   84 a, 84 b, 84 c auxiliary line    -   89 a, 89 b second recognition wall image    -   90 virtual guide wall    -   91 a, 91 b virtual side wall    -   92 a, 92 b, 92 c virtual distance wall    -   95 l ₁ to 95 l ₅, 95 r ₁ to 95 r ₅ virtual line    -   96 a, 96 b wall portion    -   97 a, 97 b floor portion    -   98 l ₁ to 98 l ₅, 98 r ₁ to 98 r ₅ first distance recognition        line    -   99 a, 99 b icon image    -   100 l, 100 r second distance recognition line    -   101, 102 view display region

The invention claimed is:
 1. An imaging apparatus comprising: an imagesensor configured to capture a rear area behind a vehicle and generate afirst video image; and a controller configured to synthesize a guidewall image that indicates a predicted path of the vehicle in a displayregion of the first video image, wherein the guide wall image includes aplurality of virtual translucent wall surfaces that extend from a roadsurface to a predetermined height in a height direction, and the guidewall image includes: two side wall images that extend in the heightdirection and a depth direction and are spaced apart from each other ina horizontal direction by a distance corresponding to a width of thevehicle; and a plurality of distance wall images that extend in theheight direction and the horizontal direction and indicate a distance inthe depth direction, the height direction, the depth direction, and thehorizontal direction correspond to three-dimensional directions of aspace captured in the first video image, and transmittance of each ofthe distance wall images increases as the height from the road surfacein the height direction increases.
 2. The imaging apparatus according toclaim 1, wherein the guide wall image includes at least one of anauxiliary line extending in the depth direction, an auxiliary lineextending in the horizontal direction, and an auxiliary line extendingin the height direction.
 3. The imaging apparatus according to claim 1,wherein the plurality of distance wall images includes a first distancewall image positioned closer to the vehicle than other distance wallimages and in a color that is different from that of the other distancewall images of the plurality of distance wall images.
 4. The imagingapparatus according to claim 2, wherein the plurality of distance wallimages includes a first distance wall image positioned closer to thevehicle than other distance wall images and in a color different fromcolors of the other distance wall images of the plurality of distancewall images, and an auxiliary line of the first distance wall image isin a color that is the same as that of the auxiliary lines of otherdistance wall images of the plurality of distance wall images.
 5. Theimaging apparatus according to claim 1, wherein the controller isfurther configured to recognize a detection object in the display regionof the first video image, and synthesize a first recognition wall imageon a vehicle side of the detection object.
 6. The imaging apparatusaccording to claim 5, wherein the controller is further configured toestimate a first distance in a horizontal direction between thedetection object and a position corresponding to the guide wall image,and change color of the first recognition wall image in accordance withthe first distance.
 7. The imaging apparatus according to claim 5,wherein the controller is configured to estimate a first position of thedetection object in the depth direction and partially or entirely changedisplay of the side wall image corresponding to the first position. 8.The imaging apparatus according to claim 5, wherein the controller isconfigured to: estimate a predicted path of the detection object;estimate a first position where the predicted path of the detectionobject and the side wall image will intersect with each other; and atleast partially change a display of a side wall image corresponding tothe first position.
 9. The imaging apparatus according to claim 7,wherein the controller is configured to partially or entirely changecolor of the side wall image corresponding to the first position. 10.The imaging apparatus according to claim 5, wherein the controller isconfigured to change a display of a guide wall image positioned fartherin the depth direction from the first recognition wall image.
 11. Theimaging apparatus according to claim 5, wherein the controller isconfigured to: synthesize a second recognition wall image in an edgeregion of a second video image on a side where the detection object islocated when the detection object is located outside of the displayregion; the second video image being a video image corresponding to thedisplay region of the first video image.
 12. The imaging apparatusaccording to claim 11, wherein the second recognition wall imageincludes: a wall portion that extends in the height direction and thedepth direction; and a floor portion that extends in the depth directionand the horizontal direction.
 13. The imaging apparatus according toclaim 12, wherein the second recognition wall image displays an iconimage that indicates a type of the detection object on the floorportion.
 14. The imaging apparatus according to claim 13, wherein thecontroller is configured to: estimate a second distance in a horizontaldirection between the detection object and a position corresponding tothe side wall image, and change a display position of the icon image inaccordance with the second distance.
 15. The imaging apparatus accordingto claim 13, wherein the floor portion is positioned on a front side ofthe guide wall image in the depth direction.
 16. An imaging apparatuscomprising: an image sensor configured to capture a rear area behind avehicle and generate a first video image; and a controller configured togenerate a synthesized image by sequentially superimposing on a displayregion of the first video image a first image and a second image, thefirst image including a first semitransparent image in which atransmittance increases from a lower portion to an upper portion of thedisplay region overlapping with a guide wall image and the second imageincluding the guide wall image that indicates a predicted path of thevehicle, wherein the first semitransparent image gradually changes froma color different from a color of the guide wall image to transparentfrom the lower portion to the upper portion, the guide wall imageincludes a plurality of virtual translucent wall surfaces that extendfrom a road surface to a predetermined height in a height direction, theguide wall image includes: two side wall images that extend in theheight direction and a depth direction and are spaced apart from eachother in a horizontal direction by a distance corresponding to a widthof the vehicle; and a plurality of distance wall images that extend inthe height direction and the horizontal direction and indicate adistance in the depth direction, and the height direction, the depthdirection, and the horizontal direction correspond to three-dimensionaldirections of a space captured in the first video image.
 17. The imagingapparatus according to claim 16, wherein the controller is furtherconfigured to: recognize a detection object in the display region of thefirst video image; and sequentially superimpose on the detection objecta third image, the third image including a second semitransparent imagein which a transmittance increases from a lower portion to an upperportion of the display region overlapping with a recognition wall image,and a fourth image, the fourth image including the recognition wallimage that indicates a presence of the detection object.
 18. The imagingapparatus according to claim 17, wherein the second semitransparentimage gradually changes its color from a color different from a color ofthe recognition wall image to transparent from a lower portion to anupper portion.